title: Walking and leisure-time activity and risk of hip fracture in postmenopausal women. Physical Activity and Colon Cancer Risk among Women in the California Teachers Study Lifestyle as a predictor for colonic neoplasia in asymptomatic individuals Obesity, physical activity, and mortality in a prospective chinese elderly cohort. Leisure Time, Occupational, and Commuting Physical Activity and the Risk of Stroke Self-experienced physical workload and risk of breast cancer. Leisure-time physical activity and ischemic stroke risk: the Northern Manhattan Stroke Study. Risk factors for 5-year mortality in older adults: the Cardiovascular Health Study. Commuting physical activity and risk of colon cancer in Shanghai, China. Exercise and risk of stroke in male physicians. Physical activity in relation to colon cancer in middle-aged men and women. Recreational Physical Activity and Cancer Risk in Subsites of the Colon (the Nord-Trøndelag Health Study) Recreational physical activity and the risk of breast cancer in postmenopausal women: the Women's Health Initiative Cohort Study. Leisure-time physical activity and the risk of primary cardiac arrest. Walking compared with vigorous physical activity and risk of type 2 diabetes in women: a prospective study. Lifetime physical activity and breast cancer risk in a multiethnic population: the San Francisco Bay area breast cancer study. Reducing frailty and falls in older persons: an investigation of Tai Chi and computerized balance training. Atlanta FICSIT Group. Frailty and Injuries: Cooperative Studies of Intervention Techniques. Relationship of changes in physical activity and mortality among older women. Physical activity and breast cancer risk: the Women's Health Study (United States) Physical activity and mortality in postmenopausal women. Physical activity and osteoporotic hip fracture risk in men. Physical Activity and Reduced Risk of Cardiovascular Events: Potential Mediating Mechanisms Customary physical activity and survival in later life: a study in Nottingham, UK. Relationship of Physical Activity and Body Mass Index to the Risk of Hypertension: A Prospective Study in Finland Exercise intensity and longevity in men. The Harvard Alumni Health Study. Frequent and occasional physical activity in the elderly: a 12-year follow-up study of mortality. Walking to Work and the Risk for Hypertension in Men: The Osaka Health Survey Grip strength changes over 27 yr in Japanese-American men. The "weekend warrior" and risk of mortality. Occupational physical activity and breast cancer risk in the upper Cape Cod cancer incidence study. All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work. Physical activity and functional limitations in older adults: a systematic review related to Canada's Physical Activity Guidelines Physical activity and risk of colorectal cancer in Japanese men and women: the Japan Public Health Center-based prospective Study Physical activity in different periods of life and the risk of breast cancer: the Norwegian-Swedish Women's Lifestyle and Health cohort study. Physical activity protects against coronary death and deaths from all causes in middle-aged men. Evidence from a 20-year follow-up of the primary prevention study in Göteborg. A prospective study of recreational physical activity and breast cancer risk. Physical activity and diabetes risk in postmenopausal women. The economic burden of physical inactivity in Canada. Population based study of social and productive activities as predictors of survival among elderly Americans Risk Factors of Stroke Incidence and Mortality: A 12‐Year Follow‐up of the Oslo Study Awareness, treatment, and control of hypertension in Canada. Physical Activity and Coronary Heart Disease Risk in Men: Does the Duration of Exercise Episodes Predict Risk? Physical activity and stroke incidence: the Harvard Alumni Health Study. Relationship of physical fitness vs body mass index with coronary artery disease and cardiovascular events in women. Long-term recreational physical activity and risk of invasive and in situ breast cancer: the California teachers study. Change in lifestyle factors and their influence on health status and all-cause mortality. Physical activity recommendations and decreased risk of mortality. Cardiorespiratory fitness and the incidence of type 2 diabetes: prospective study of Japanese men. Physical activity and risk of myocardial infarction after the fourth decade of life. Self-reported physical activity predicts long-term coronary heart disease and all-cause mortalities. Twenty-one-year follow-up of the Israeli Ischemic Heart Disease Study. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. Physical activity and incident hypertension in black and white adults: the Atherosclerosis Risk in Communities Study. Physical Activity and Risk of Colon and Rectal Cancers: The European Prospective Investigation into Cancer and Nutrition Leisure-time physical activity, body size, and colon cancer in women. Nurses' Health Study Research Group. Physical Activity, Obesity, and Risk for Colon Cancer and Adenoma in Men Past physical activity, current physical activity, and risk of coronary heart disease. Physical activity is associated with incident disability in community-based older persons. Physical activity and breast cancer risk in a cohort of young women. Can a simple measure of vigorous physical activity predict future mortality? Results from the OXCHECK study. The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. The long-term effect of physical activity on incidence of coronary heart disease: a 12-year follow-up study. Occupational, commuting, and leisure-time physical activity in relation to risk for Type 2 diabetes in middle-aged Finnish men and women Walking compared with vigorous exercise for the prevention of cardiovascular events in women. Long-term physical activity in leisure time and mortality from coronary heart disease, stroke, respiratory diseases, and cancer. The Copenhagen City Heart Study What level of physical activity protects against premature cardiovascular death? The Caerphilly study Television watching and other sedentary behaviors in relation to risk of obesity and type 2 diabetes mellitus in women. Resistance and agility training reduce fall risk in women aged 75 to 85 with low bone mass: a 6-month randomized, controlled trial. Relationship of physical activity vs body mass index with type 2 diabetes in women. The Association between Cardiorespiratory Fitness and Impaired Fasting Glucose and Type 2 Diabetes Mellitus in Men Physical activity and breast cancer risk in hispanic and non-hispanic white women. A single weekly bout of exercise may reduce cardiovascular mortality: how little pain for cardiac gain? 'The HUNT study, Norway'. Physical activity and the risk of colon cancer among women: a prospective cohort study (United States). Moderately intense physical activities and high levels of cardiorespiratory fitness reduce the risk of non-insulin-dependent diabetes mellitus in middle-aged men. Changes in physical fitness and all-cause mortality. A prospective study of healthy and unhealthy men. Physical activity and cause-specific mortality in the Whitehall study. Leisure-time physical activity and the risk of nonfatal myocardial infarction in postmenopausal women. A prospective study of exercise and incidence of diabetes among US male physicians. Work and leisure time physical activity and mortality in men and women from a general population sample. Physical activity in usual occupation and risk of breast cancer (United States) Low physical activity as a predictor for total and cardiovascular disease mortality in middle-aged men and women in Finland. A prospective study of walking as compared with vigorous exercise in the prevention of coronary heart disease in women. Physical activity and stroke mortality in women. Ten-year follow-up of the Nord-Trondelag health survey, 1984-1986. The economic costs associated with physical inactivity and obesity in Canada: an update. The Risk of Acute Myocardial Infarction: Interactions of Types of Physical Activity Physical Activity and Coronary Event Incidence in Northern Ireland and France: The Prospective Epidemiological Study of Myocardial Infarction (PRIME) Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. Walking to Work Is an Independent Predictor of Incidence of Type 2 Diabetes in Japanese Men Physical activity and incidence of diabetes: the Honolulu Heart Program. The effects of physical activity and body mass index on cardiovascular, cancer and all-cause mortality among 47 212 middle-aged Finnish men and women Association of Energy Intake and Energy Balance with Postmenopausal Breast Cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Combined Work and Leisure Physical Activity and Risk of Stroke in Men and Women in the European Prospective Investigation into Cancer-Norfolk Prospective Population Study Recreational physical activity and risk of postmenopausal breast cancer in a large cohort of US women Physical Activity and Breast Cancer Risk: The European Prospective Investigation into Cancer and Nutrition Relationship of leisure-time physical activity and mortality: the Finnish twin cohort. Physical activity and incidence of non-insulin-dependent diabetes mellitus in women A multifactorial intervention to reduce the risk of falling among elderly people living in the community. Body mass index, physical inactivity and low level of physical fitness as determinants of all-cause and cardiovascular disease mortality—16 y follow-up of middle-aged and elderly men and women Physical activity and stroke risk: the Framingham Study. Stroke risk in older men and women: aspirin, estrogen, exercise, vitamins, and other factors. Exercise effects on bone mass in postmenopausal women are site-specific and load-dependent. Results of a 10 week community based strength and balance training programme to reduce fall risk factors: a randomised controlled trial in 65–75 year old women with osteoporosis Changes in physical activity, mortality, and incidence of coronary heart disease in older men Physical activity, functional limitations, and the risk of fall-related fractures in community-dwelling elderly. Occurrence of Breast Cancer in Relation to Recreational Exercise in Women Age 50‐64 Years Does walking decrease the risk of cardiovascular disease hospitalizations and death in older adults? Leisure time physical activity and the 16-year risks of mortality from coronary heart disease and all-causes in the Multiple Risk Factor Intervention Trial (MRFIT). Relationship between components of leisure physical activity and mortality in Taiwanese older adults. Cardiorespiratory fitness and stroke mortality in men.
abstract: CONTEXT Physical activity can reduce the risk of  hip fractures in older women , although the required type and duration of activity have not been determined . Walking is the most common activity among older adults , and evidence suggests that it can increase femoral bone density and reduce fracture risk . OBJECTIVE To assess the relationship of walking , leisure-time activity , and risk of hip fracture among postmenopausal women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve analysis begun in 1986 with 12 years of follow-up in the Nurses ' Health Study cohort of registered nurses within 11 US states . A total of 61,200 postmenopausal women ( aged 40 - 77 years and 98 % white ) without diagnosis of cancer , heart disease , stroke , or osteoporosis at baseline . MAIN OUTCOME MEASURES Incident hip fracture result ing from low or moderate trauma , analyzed by intensity and duration of leisure-time activity  and by  time spent walking , sitting , and st and ing  , measured at baseline and up date d throughout follow-up . RESULTS From 1986 to 1998 , 415 incident hip fracture cases were identified . After controlling for age , body mass index , use of postmenopausal hormones , smoking , and dietary intakes in proportional hazards models , risk of hip fracture was lowered by 6 % ( 95 % confidence interval [ CI ] , 4%-9 % ; P<.001 ) for each increase of 3 metabolic equivalent (MET)-hours per week of activity ( equivalent to 1 h/wk of walking at an average pace ) . Active women with at least 24 MET-h/wk had a 55 % lower risk of hip fracture ( relative risk [ RR ] , 0.45 ; 95 % CI , 0.32 - 0.63 ) compared with sedentary women with less than 3 MET-h/wk . Even women with a lower risk of hip fracture due to higher body weight experienced a further reduction in risk with higher levels of activity . Risk of hip fracture decreased linearly with increasing level of activity among women not taking postmenopausal hormones ( P<.001 ) , but not among women taking hormones ( P = .24 ) . Among women who did no other exercise , walking for at least 4 h/wk was associated with a 41 % lower risk of hip fracture ( RR , 0.59 ; 95 % CI , 0.37 - 0.94 ) compared with less than 1 h/wk . More time spent st and ing was also independently associated with lower risks . CONCLUSION Moderate levels of activity , including walking , are associated with substantially lower risk of hip fracture in postmenopausal women Background : Existing data suggest that physical activity reduces colon cancer risk , but the association is not consistently observed in women . One potential explanation for this inconsistency is that hormone therapy , which is associated with lower colon cancer risk , acts as a modifier of the physical activity/colon cancer relationship . Methods : Participants in the California Teachers Study ( N = 120,147 ) , a prospect i ve cohort of female teachers and administrators residing in California , ages 22 to 84 years at baseline and with no prior history of colon cancer were eligible for study . Between 1996 and 2002 , 395 patients were diagnosed with invasive colon cancer . The relative risks ( RR ) associated with lifetime ( high school through age 54 years or current age ) and recent ( past 3 years ) strenuous and moderate recreational physical activity were estimated using Cox proportional hazards regression models . Results : Combined lifetime moderate and strenuous recreational physical activity was only modestly associated with colon cancer risk in the cohort [ ≥4 versus ≤0.5 h/wk/y : RR , 0.75 ; 95 % confidence interval , 0.57 - 1.00 ; Ptrend = 0.23 ] . Lifetime physical activity reduced colon cancer risk among postmenopausal women who had never taken hormone therapy ( ≥4 versus ≤0.5 h/wk/y : RR , 0.51 ; 95 % confidence interval , 0.31 - 0.85 ; Ptrend = 0.02 ) . Postmenopausal women with histories of hormone therapy use had lower colon cancer risk , but their risk was not associated with physical activity . The likelihood ratio test for interaction between hormone use and lifetime moderate plus strenuous physical activity was of borderline statistical significance ( P = 0.05 ) . We observed no effect modification by age , body mass index , smoking status , menopausal status , or folate intake . Conclusions : Lifetime recreational physical activity may protect against colon cancer among postmenopausal women who have never used hormone therapy . Among hormone therapy users , who have lower risk of colon cancer , recreational physical activity does not seem to provide any additional benefit . With declining rates of hormone therapy use , physical activity offers one possible means for reducing women 's colon cancer risk . ( Cancer Epidemiol Biomarkers Prev 2007;16(3):517–25 Background Lifestyle is a well-established risk factor for colorectal cancer ( CRC ) and is also found to be associated with occurrence of adenomas . In the present study we evaluated risk factors for both low-risk adenomas and advanced neoplasia  in asymptomatic individuals using a single-paged question naire . Aim ing to see if the question naire was a useful tool in picking up high-risk individuals . Methods A cross-sectional study was carried out within a r and omised controlled colorectal cancer screening trial ( n = 6961 ) . The population comprised men and women born between 1946 and 1950 . Before screening in year 2001 they were asked to fill in a question naire about their present lifestyle . Cases were categorised according to the most severe findings at screening . Analyses were then conducted to find risk factors associated with the presence of either low-risk adenomas or advanced neoplasia . Results The response rate among attendees was 97 % ( 3998/4111 ) . Among these , 3447 ( 86 % ) had no neoplasia , 443 ( 11 % ) had low-risk adenomas , and 108 ( 3 % ) had advanced neoplasia . Low-risk adenomas were significantly associated with current smoking , and obesity .  Participants with advanced neoplasia had a two-fold increased risk of not adhering to any of the selected lifestyle recommendations compared to controls . However , current smoking was the only variable that reached statistical significance in the multivariate analysis for these lesions . A dose-response relationship to the consumption of cigarettes per day was shown , where OR was 2.04 ( CI 1.07–3.89 ) for the lowest consumption category . Conclusion The present findings indicate that a short question naire may be adequate in picking up the most consistent associations between lifestyle risk factors and colorectal neoplasia . Smoking and BMI were found to be the most significant risk factors for neoplasia , but adhering to recommendations on diet , and physical activity seems also to be of importance BACKGROUND In older people , it is unclear whether obesity relates to mortality , which calls into question its etiologic role in disease and its public health relevance . This apparent lack of relationship in older people could be an artifactual result of their diverse health states . METHODS We used Cox regression analysis to determine whether the effect of body mass index ( BMI ) ( calculated as weight in kilograms divided by the square of height in meters ) or physical activity on mortality varied with health status in a prospect i ve cohort study of Chinese people 65 years or older enrolled from 1998 to 2000 at all of the 18 Elderly Health Centers of the Hong Kong Government Department of Health . Health status was categorized into 5 morbidity groups using a 12-item index covering illnesses , medications , frailty , and smoking . RESULTS After a mean follow-up of 4.1 years , there were 3819 deaths in 54 088 subjects ( 96.5 % successful follow-up ) . The effect of BMI on mortality varied with baseline health status ( P<.001 ) . In the healthiest group , obese people ( BMI > /=25 ) had higher mortality ( adjusted hazard ratio [ HR ] , 1.54 ; 95 % confidence interval [ CI ] , 1.02 - 2.33 ) , but in the unhealthiest group they had lower mortality ( HR , 0.55 ; 95 % CI , 0.49 - 0.63 ) compared with subjects of normal weight . Daily physical activity was associated with lower mortality compared with inactivity in the unhealthiest group ( HR , 0.70 ; 95 % CI , 0.61- 0.81 ) but not in the healthiest group . CONCLUSIONS In the elderly , the relationship between obesity and mortality varies according to the underlying health status . In those with poor health status , obesity is associated with better outcome , whereas in those with initially good health status , obesity is associated with worse outcome Background and Purpose — The role of physical activity , especially that of occupational and commuting physical activity , in the prediction of stroke risk is not properly established . We assessed the relationship of different types of physical activity with total and type-specific stroke risk . Methods — We prospect ively followed 47 721 Finnish subjects 25 to 64 years of age without a history of coronary heart disease , stroke , or cancer at baseline .  Hazard ratios ( HRs ) for incident stroke were estimated for different levels of leisure time , occupational , and commuting physical activity . Results — During a mean follow-up of 19.0 years , 2863 incident stroke events were ascertained . The multivariate-adjusted ( age , sex , area , study year , body mass index , systolic blood pressure , cholesterol , education , smoking , alcohol consumption , diabetes , and other 2 types of physical activity ) HRs associated with low , moderate , and high leisure time physical activity were 1.00 , 0.86 , and 0.74 ( Ptrend<0.001 ) for total stroke , 1.00 , 0.87 , and 0.46 ( Ptrend=0.011 ) for subarachnoid hemorrhage , 1.00 , 0.77 , and 0.63 ( Ptrend=0.024 ) for intracerebral hemorrhage , and 1.00 , 0.87 , and 0.80 ( Ptrend=0.001 ) for ischemic stroke , respectively . The multivariate-adjusted HRs associated with none , 1 to 29 , and ≥30 minutes of active commuting were 1.00 , 0.92 , and 0.89 ( Ptrend=0.043 ) for total stroke , and 1.00 , 0.93 , and 0.86 ( Ptrend=0.028 ) for ischemic stroke , respectively . Occupational activity had a modest association with ischemic stroke in the multivariate analysis ( Ptrend=0.046 ) . Conclusion — A high level of leisure time physical activity  reduces the risk of all subtypes of stroke . Daily active commuting also reduces the risk of ischemic stroke OBJECTIVES The association between the risk of breast cancer and the physical load of work was studied because physical activity may reduce breast cancer risk via hormonal mechanisms . METHODS Occupational physical activity was estimated from a self-determined rating [ scale 1 (low)-5 ( high ) ] of occupational physical load for 1800 r and omly selected women born in 1930 - 1969 . The medians of the ratings were used as occupation-specific indices of occupational physical activity . All 65 occupations with at least 5 ratings , covering 75 % of the economically active female population in Finl and , were included in further analyses . The occupation-specific numbers of observed and expected cases of breast cancer during 1971 - 1995 among women born in 1906 - 1945 ( 17,986 cases ) were grouped according to the index for occupational physical activity . Expected rates were calculated with the social-class-specific population and the entire Finnish female population as reference population s. The relative risks ( RR ) of breast cancer for categories 3 - 5 , in comparison with categories 1 - 2 were calculated using Poisson regression models . The occupation-specific mean number of children and mean age at first childbirth were adjusted for . RESULTS The RR was lower for occupations in category 5 than for those in categories 1 - 4 , especially in the youngest ( 25 - 39 years ) age group ( RR 0.51 , 95 % confidence interval 0.44 - 0.58 ) . Adjustment for social class and reproductive factors raised the RR ( 95 % confidence interval 0.56 - 0.74 ) for category 5 in different age strata , all the RR values still being statistically significant . CONCLUSIONS The results support the hypothesis that occupational physical activity , if high enough , markedly reduces breast cancer risk BACKGROUND AND PURPOSE Physical activity reduces the risk of premature death and cardiovascular disease , but the relationship to stroke is less well studied . The objective of this study was to investigate the association between leisure-time physical activity and  ischemic stroke in an urban , elderly , multiethnic population . METHODS The Northern Manhattan Stroke Study is a population -based incidence and case-control study . Case subjects had first ischemic stroke , and control subjects were derived through r and om-digit dialing with 1:2 matching for age , sex , and race/ethnicity .  Physical activity  was recorded through a st and ardized in-person interview regarding the frequency and duration of 14 activities over the 2 prior weeks . Conditional logistic regression was used to calculate odds ratios ( OR ) and 95 % confidence intervals after adjustment for medical and socioeconomic confounders . RESULTS Over 30 months , 369 case subjects and 678 control subjects were enrolled . Mean age was 69.9 + /- 12 years ; 57 % were women , 18 % whites , 30 % blacks , and 52 % Hispanics .  Leisure-time physical activity  was significantly protective for stroke after adjustment for cardiac disease , peripheral vascular disease , hypertension , diabetes , smoking , alcohol use , obesity , medical reasons for limited activity , education , and season of enrollment ( OR = 0.37 ; 95 % confidence interval=0.25 to 0.55 ) . The protective effect of  physical activity  was detected in both younger and older groups , in men and women , and in whites , blacks , and Hispanics . A dose-response relationship was shown for both intensity ( light-moderate activity OR = 0.39 ; heavy OR = 0.23 ) and duration ( < 2 h/wk OR = 0.42 ; 2 to < 5 h/wk OR = 0.35 ; > or = 5 h/wk OR = 0.31 ) of physical activity . CONCLUSIONS Leisure-time physical activity was related to a decreased occurrence of ischemic stroke in our elderly , multiethnic , urban subjects . More emphasis on physical activity in stroke prevention campaigns is needed among the elderly CONTEXT Multiple factors contribute to mortality in older adults , but the extent to which sub clinical disease and other factors contribute independently to mortality risk is not known . OBJECTIVE To determine the disease , functional , and personal characteristics that jointly predict mortality in community-dwelling men and women aged 65 years or older . DESIGN Prospect i ve population -based cohort study with 5 years of follow-up and a validation cohort of African Americans with 4.25-year follow-up . SETTING Four US communities . PARTICIPANTS A total of 5201 and 685 men and women aged 65 years or older in the original and African American cohorts , respectively . MAIN OUTCOME MEASURES Five-year mortality . RESULTS In the main cohort , 646 deaths ( 12 % ) occurred within 5 years . Using Cox proportional hazards models , 20 characteristics ( of 78 assessed ) were each significantly ( P<.05 ) and independently associated with mortality : increasing age , male sex , income less than $ 50000 per year , low weight , lack of moderate or vigorous exercise , smoking for more than 50 pack-years , high brachial ( > 169 mm Hg ) and low tibial ( < or = 127 mm Hg ) systolic blood pressure , diuretic use by those without hypertension or congestive heart failure , elevated fasting glucose level ( > 7.2 mmol/L [ 130 mg/dL ] ) , low albumin level ( < or = 37 g/L ) , elevated creatinine level ( > or = 106 micromol/L [ 1.2 mg/dL ] ) , low forced vital capacity ( < or = 2.06 mL ) , aortic stenosis ( moderate or severe ) and abnormal left ventricular ejection fraction ( by echocardiography ) , major electrocardiographic abnormality , stenosis of internal carotid artery ( by ultrasound ) , congestive heart failure , difficulty in any instrumental activity of daily living , and low cognitive function by Digit Symbol Substitution test score . Neither high-density lipoprotein cholesterol nor low-density lipoprotein cholesterol was associated with mortality . After adjustment for other factors , the association between age and mortality diminished , but the reduction in mortality with female sex persisted . Finally , the risk of mortality was vali date d in the second cohort ; quintiles of risk ranged from 2 % to 39 % and 0 % to 26 % for the 2 cohorts . CONCLUSIONS Objective measures of sub clinical disease and disease severity were independent and joint predictors of 5-year mortality in older adults , along with male sex , relative poverty , physical activity , smoking , indicators of frailty , and disability . Except for history of congestive heart failure , objective , quantitative measures of disease were better predictors of mortality than was clinical history of disease Colon cancer incidence rates have been rapidly increasing in Shanghai , China , for reasons still unclear . Low physical activity is a known risk factor for colon cancer . The authors examined the effects of physical activity , particularly commuting physical activity , and its joint effects with body mass index on colon cancer risk in a population -based , case-control study . The study included 931 incident colon cancer patients and 1,552 r and omly selected controls in Shanghai between 1990 and 1993 .  Colon cancer risk was significantly reduced among subjects with high commuting physical activity ( odds ratio ( OR ) = 0.52 , 95 % confidence interval ( CI ) : 0.27 , 0.87 for men ; OR = 0.56 , 95 % CI : 0.21 , 0.91 for women ) , particularly among those who had high commuting physical activity for at least 35 years ( OR = 0.34 , 95 % CI : 0.09 , 0.76 for men ; OR = 0.31 , 95 % CI : 0.07 , 0.72 for women ) . Commuting physical activity significantly modified the risk conferred by high body mass index , with the highest risk observed among those at the highest quintile of body mass index and the lowest activity level ( OR = 6.43 , 95 % CI : 1.82 , 8.54 for men ; OR = 7.42 , 95 % CI : 2.84 , 10.01 for women ) . Our results suggest that regular and frequent physical activity over a long period of time protects from colon cancer and significantly modifies the body mass index-associated risk BACKGROUND AND PURPOSE From a physiological perspective , physical activity might be expected to decrease the risk of developing stroke . However , epidemiological studies of physical activity and stroke risk have yielded divergent findings . We therefore sought to examine the association between exercise and stroke risk . METHODS This was a prospect i ve cohort study of 21 823 men , followed up for an average of 11.1 years . Participants were from the Physicians ' Health Study , a r and omized trial of low-dose aspirin and beta carotene . Men , aged 40 to 84 years at baseline , were free of self-reported myocardial infa rct ion , stroke , transient ischemic attack , and cancer . At baseline , they reported on the frequency of exercise vigorous enough to work up a sweat . Stroke occurrence was reported by participants and confirmed after medical record review ( n=533 ) . We used Cox proportional hazards regression to analyze the data . RESULTS With adjustment for age , treatment assignment , smoking , alcohol intake , history of angina , and parental history of myocardial infa rct ion , the relative risks of total stroke associated with vigorous exercise < 1 time , 1 time , 2 to 4 times , and > /=5 times per week at baseline were 1.00 ( referent ) , 0.79 ( 95 % confidence interval [ CI ] , 0.61 to 1 . 03 ) , 0.80 ( 95 % CI , 0.65 to 0.99 ) , and 0.79 ( 95 % CI , 0.61 to 1.03 ) , respectively ; P for trend=0.04 . In subgroup analyses , the inverse association appeared stronger with hemorrhagic than ischemic stroke . When we additionally adjusted for body mass index , history of hypertension , high cholesterol , and diabetes mellitus , corresponding relative risks for total stroke were 1.00 ( referent ) , 0.81 ( 95 % CI , 0.61 to 1.07 ) , 0.88 ( 95 % CI , 0.70 to 1.10 ) , and 0.86 ( 95 % CI , 0.65 to 1.13 ) , respectively ; P for trend=0.25 . CONCLUSIONS Exercise vigorous enough to work up a sweat is associated with decreased  stroke risk in men . In the present study , the inverse association with physical activity appeared to be mediated through beneficial effects on body weight , blood pressure , serum cholesterol , and glucose tolerance . Apart from its favorable influences on these variables , physical activity had no significant residual association with stroke incidence A population -based case-control study was conducted to assess the relation between physical activity  and colon cancer among men and women aged 30 - 62 years . Cases were 251 men and 193 women diagnosed with colon cancer in 1985 - 1989 in three countries in the Seattle metropolitan area who were identified from the Seattle-Puget Sound Surveillance , Epidemiology , and End Results registry . Controls were 233 men 194 women identified by r and om digit telephone dialing who were selected by stratified r and om sampling to approximate the age , sex , and county distribution of cases .  Physical activity  was assessed by questions on frequency and duration of types of recreational and occupational activities  during the 10-year period ending 2 years before diagnosis . Each activity was classified as low intensity ( < 4.5 METs ) or moderate to high intensity ( > or = 4.5 METs ) . For men and women combined , moderate or high intensity recreational activity was associated with a decreased risk of colon cancer ( relative risk ( RR ) for two or more times per week vs. none = 0.70 , 95 % confidence interval ( CI ) 0.49 - 1.00 ) . This relation was stronger for men than women . Occupational activity was not associated with colon cancer , except among men younger than 55 ( RR for > or = 14.5 hours per week of moderate activity vs. none = 0.29 , 95 % CI 0.12 - 0.69 ) . Among men and women combined , total moderate or high intensity activity ( occupational plus recreational ) was marginally related to colon cancer ( RR for > or = 5 hours per week vs. none = 0.78 , 95 % CI 0.55 - 1.10 ) . These results were adjusted for age ( and sex in the combined sex analyses ) and were not confounded by body mass index , dietary factors , or other measured health behaviors . The results of this study provide modest support to the growing number of studies showing that recreational and /or occupational physical activity is associated with a reduced risk of colon cancer Physical activity may reduce colon cancer risk , but the underlying mechanisms remain unclear . Relating physical activity to cancer risk in anatomic segments of the colon may advance our underst and ing of possible mechanisms . We conducted a prospect i ve study of 59,369 Norwegian men and women who were followed up for cancer incidence and mortality . Cox proportional hazards models were used to estimate multivariably adjusted hazard ratios ( HR ) and 95 % confidence intervals ( 95 % CI ) . All statistical tests were two sided . During 17 years of follow-up , 736 colon cancers and 294 rectal cancers were diagnosed . Overall , we found an inverse association between  recreational physical activity  and colon cancer risk , but subsite analyses showed that the association was confined to cancer in the transverse and sigmoid colon . The adjusted HR , comparing people who reported high versus no physical activity , was 0.44 ( 95 % CI , 0.25 - 0.78 ) for cancer in the transverse colon and 0.48 ( 95 % CI , 0.31 - 0.75 ) for cancer in the sigmoid colon . The corresponding HR for cancer mortality was 0.33 ( 95 % CI , 0.14 - 0.76 ) for the transverse colon and 0.29 ( 95 % CI , 0.15 - 0.56 ) for the sigmoid colon . For rectal cancer , there was no association with physical activity in these data . In conclusion , the inverse association of recreational physical activity with cancer risk and mortality in the transverse and sigmoid segments of the colon may point at increased colon motility and reduced fecal transit time as possible underlying mechanisms . ( Cancer Epidemiol Biomarkers Prev 2008;17(1):183–8 CONTEXT Women who are  physically active  have a decreased risk for breast cancer , but the types , amounts , and timing of activity needed are unknown . OBJECTIVE To prospect ively examine the association between current and past recreational physical activity and incidence of  breast cancer in postmenopausal women . DESIGN , SETTING , AND PATIENTS Prospect i ve cohort study in 74 171 women aged 50 to 79 years who were recruited by 40 US clinical centers from 1993 through 1998 . MAIN OUTCOME MEASURE Incident invasive and in situ breast cancer . RESULTS We documented 1780 newly diagnosed cases of breast cancer over a mean follow-up of 4.7 years . Compared with less active women , women who engaged in regular strenuous physical activity at age 35 years had a 14 % decreased risk of breast cancer ( relative risk [ RR ] , 0.86 ; 95 % confidence interval [ CI ] , 0.78 - 0.95 ) . Similar but attenuated findings were observed for strenuous physical activity at ages 18 years and 50 years . An increasing total current physical activity score was associated with a reduced risk for breast cancer ( P = .03 for trend ) . Women who engaged in the equivalent of 1.25 to 2.5 hours per week of brisk walking had an 18 % decreased risk of breast cancer ( RR , 0.82 ; 95 % CI , 0.68 - 0.97 ) compared with inactive women . Slightly greater reduction in risk was observed for women who engaged in the equivalent of 10 hours or more per week of brisk walking . The effect of exercise  was most pronounced in women in the lowest tertile of body mass index ( BMI ) ( < 24.1 ) , but also was observed for women in the middle tertile of BMI ( 24.1 - 28.4 ) . CONCLUSIONS These data suggest that increased physical activity is associated with reduced risk for breast cancer in postmenopausal women , longer duration provides most benefit , and that such activity need not be strenuous BACKGROUND Because the risks of sudden cardiac death and myocardial infa rct ion are transiently increased during acute bouts of high-intensity activity , it is an important question from the public health perspective whether regular participation in moderate-intensity activity confers overall protection from sudden cardiac death . PARTICIPANTS AND METHODS We used data from a population -based case-control study to assess the associations of regular high-intensity and moderate-intensity leisure-time physical activity with  primary cardiac arrest . Cases were patients with primary cardiac arrest , aged 25 to 74 years , attended by paramedics between 1988 and 1994 in King County , Washington ( n = 333 ) . Controls were r and omly identified from the same community ( n = 503 ) , matched for age and sex . All case patients and controls were free of prior clinical heart disease , major comorbidity , and self-reported poor health . Spouses of case patients and controls were interviewed to assess participation in 15 high-intensity and 6 moderate-intensity physical activities during the prior year . RESULTS Compared with subjects who performed none of the activities , the odds ratio for primary cardiac arrest from matched analyses was 0.34 ( 95 % confidence interval , 0.13 - 0.89 ) among subjects who performed only gardening activities for more than 60 minutes per week ; 0.27 ( 95 % confidence interval , 0.11 - 0.67 ) among subjects who walked for exercise for more than 60 minutes per week ; and 0.34 ( 95 % confidence interval , 0.16 - 0.75 ) among subjects who engaged in any high-intensity activities , after adjustment for age , smoking , education , diabetes , hypertension , and health status . CONCLUSIONS The results suggest that regular participation in moderate-intensity activities , such as walking and gardening , are associated with a reduced risk of PCA and support current exercise recommendations CONTEXT Although many studies suggest that physical activity may reduce risk of type 2 diabetes , the role of moderate-intensity activity such as walking is not well understood . OBJECTIVES To examine the relationship of total physical activity and incidence of type 2 diabetes in women and to compare the benefits of walking vs vigorous activity as predictors of subsequent risk of type 2 diabetes . DESIGN AND SETTING The Nurses ' Health Study , a prospect i ve cohort study that included detailed data for physical activity from women surveyed in 11 US states in 1986 , with up date s in 1988 and 1992 . PARTICIPANTS A total of 70,102 female nurses aged 40 to 65 years who did not have diabetes , cardiovascular disease , or cancer at baseline ( 1986 ) . MAIN OUTCOME MEASURE Risk of type 2 diabetes by quintile of metabolic equivalent task ( MET ) score , based on time spent per week on each of 8 common physical activities , including  walking .  RESULTS During 8 years of follow-up ( 534 , 928 person-years ) , we documented 1419 incident cases of type 2 diabetes . After adjusting for age , smoking , alcohol use , history of hypertension , history of high cholesterol level , and other covariates , the relative risks ( RRs ) of developing type 2 diabetes across quintiles of physical activity ( least to most ) were 1.0 , 0.77 , 0.75 , 0.62 , and 0.54 ( P for trend < .001 ) ; after adjusting for body mass index ( BMI ) , RRs were 1.0 , 0.84 , 0.87 , 0.77 , and 0.74 ( P for trend = .002 ) . Among women who did not perform vigorous activity , multivariate RRs of type 2 diabetes across quintiles of MET score for walking were 1.0 , 0.91,0.73 , 0.69 , and 0.58 ( P for trend < .001 ) . After adjusting for BMI , the trend remained statistically significant ( RRs were 1.0 , 0.95 , 0.80 , 0.81 , 0.74 ; P for trend = .01 ) . Faster usual walking pace was independently associated with decreased risk . Equivalent energy expenditures from walking and vigorous activity result ed in comparable magnitudes of risk reduction . CONCLUSIONS Our data suggest that greater physical activity level is associated with substantial reduction in risk of type 2 diabetes , including physical activity of moderate intensity and duration Considerable epidemiological data have accumulated in support of a lower risk of breast cancer among physically active women . Few studies , however , have examined the relation with lifetime physical activity from all sources , and moderate activity in particular . We conducted a population -based case-control study of breast cancer in Latinas , African Americans , and whites aged 35 - 79 years to assess the association with lifetime histories of moderate and vigorous physical activity , including recreational activity , walking , bicycling , household and outdoor chores , and occupation .  Patients diagnosed with invasive breast cancer between 1995 and 1998 were identified through the cancer registry in the San Francisco Bay area , and a r and om sample of women without breast cancer was identified through r and om-digit dialing . A structured question naire administered in-person was completed by 403 premenopausal cases and 483 controls and 847 postmenopausal cases and 1065 controls . Summing activities from all sources over an individual 's lifetime , we found reduced breast cancer risk in both pre- and postmenopausal women with the highest versus lowest tertile of average lifetime activity ( premenopausal : multivariate adjusted odds ratio = 0.74 , 95 % confidence interval = 0.52 - 1.05 ; postmenopausal : odds ratio = 0.81 , 95 % confidence interval = 0.64 - 1.02 ) , with similar reductions in the three racial/ethnic groups . In premenopausal women , risk reductions were similar for different types of activities , whereas in postmenopausal women , they were limited to occupational activity . Considering the intensity of activities , risk reductions were similar for moderate and vigorous activities . Because few of the currently known risk factors for breast cancer are modifiable , these results underline the public health importance of promoting physically active lifestyles OBJECTIVE To evaluate the effects of two exercise approaches , Tai Chi ( TC ) and computerized balance training ( BT ) , on specified primary outcomes ( biomedical , functional , and psychosocial indicators of frailty ) and secondary outcomes ( occurrence of falls ) . DESIGN The Atlanta FICSIT ( Frailty and Injuries : Cooperative Studies of Intervention Techniques ) , a prospect i ve , r and omized , controlled clinical trial with three arms ( TC , BT , and education [ ED ] . Intervention length was 15 weeks , with primary outcomes measured before and after intervention and at 4-month follow-up . Falls were monitored continuously throughout the study . SETTING Persons aged 70 and older living in the community . PARTICIPANTS A total of 200 participants , 162 women and 38 men ; mean age was 76.2 . MEASUREMENTS Biomedical ( strength , flexibility , cardiovascular endurance , body composition ) , functional ( IADL ) , and psychosocial well-being ( CES-D scale , fear of falling question naire , self-perception of present and future health , mastery index , perceived quality of sleep , and intrusiveness ) variables . RESULTS Grip strength declined in all groups , and lower extremity range of motion showed limited but statistically significant changes . Lowered blood pressure before and after a 12-minute walk was seen following TC participation . Fear of falling responses and intrusiveness responses were reduced after the TC intervention compared with the ED group ( P = .046 and P = .058 , respectively ) . After adjusting for fall risk factors , TC was found to reduce the risk of multiple falls by 47.5 % . CONCLUSIONS A moderate TC intervention can impact favorably on defined biomedical and psychosocial indices of frailty . This intervention can also have favorable effects upon the occurrence of falls .  Tai Chi warrants further study as an exercise treatment to improve the health of older people CONTEXT Physical activity has been related to reduced mortality , but it is not clear whether changes in physical activity affect mortality among older women . OBJECTIVE To examine the relationship of changes in physical activity and mortality  among older women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study conducted at 4 US research centers ( Baltimore , Md ; Portl and , Ore ; Minneapolis , Minn ; and Monongahela Valley , Pa ) among 9518 community-dwelling white women aged 65 years or older who were assessed at baseline ( 1986 - 1988 ) , 7553 of whom were reassessed at a follow-up visit ( 1992 - 1994 ; median , 5.7 years later ) . MAIN OUTCOME MEASURES  Walking and other physical activities at baseline and follow-up ; vital status , with cause of death confirmed by death certificates/discharge summaries , tracked for up to 12.5 years after baseline ( up to 6.7 years after the follow-up visit ) . RESULTS Compared with continually sedentary women , those who increased physical activity levels between baseline and follow-up had lower mortality from all causes ( hazard rate ratio [ HRR ] , 0.52 ; 95 % confidence interval [ CI ] , 0.40 - 0.69 ) , cardiovascular disease ( HRR , 0.64 ; 95 % CI , 0.42 - 0.97 ) , and cancer ( HRR , 0.49 ; 95 % CI , 0.29 - 0.84 ) , independent of age , smoking , body mass index , comorbid conditions , and baseline physical activity level . Associations between changes in physical activity and reduced mortality were similar in women with and without chronic diseases but tended to be weaker among women aged at least 75 years and among those with poor health status . Women who were physically active at both visits also had lower all-cause mortality ( HRR , 0.68 ; 95 % CI , 0.56 - 0.82 ) and cardiovascular mortality ( HRR , 0.62 ; 95 % CI , 0.44 - 0.88 ) than sedentary women . CONCLUSION Increasing and maintaining physical activity levels could lengthen life for older women but appears to provide less benefit for women aged at least 75 years and those with poor health status Abstract Objective : It is biologically plausible for physical activity to decrease breast cancer risk ; however , epidemiologic studies have yielded inconsistent findings . We therefore examined physical activity and breast cancer risk in the Women 's Health Study . Methods : We assessed physical activity among 39,322 apparently healthy women , aged ≥45 years , and prospect ively followed them for an average of 48 months . Four hundred eleven women developed breast cancer , with 222 positive for both estrogen and progesterone receptors . Results : Among all women the multivariate relative risks of all breast cancer associated with < 840 , 840–2519 , 2520–6299 , and ≥6300 kJ/week expended on recreational activities and stair climbing  were 1.00 ( referent ) , 1.04 ( 95 % confidence interval , 0.77–1.40 ) , 0.86 ( 0.64–1.17 ) , and 0.80 ( 0.58–1.12 ) , respectively ; p-trend = 0.11 . However , among postmenopausal women there was a significant inverse trend for all breast cancer ; the corresponding relative risks were 1.0 ( referent ) , 0.97 ( 0.68–1.4 ) , 0.78 ( 0.54–1.1 ) , and 0.67 ( 0.44–1.0 ) , respectively ; p-trend = 0.03 . Physical activity was unrelated to breast cancers positive for both estrogen and progesterone receptors either among all or postmenopausal women ( p-trend = 0.50 and 0.26 , respectively ) . When we assessed only vigorous recreational activity , requiring ≥6 METs or multiples of resting metabolic rate , we observed no significant associations with all or steroid hormone receptor positive breast cancer , either among all or postmenospausal women . Conclusions : These data suggest that physical activity during middle age and older is not uniformly associated with decreased breast cancer risk . Among postmenopausal women only , higher levels of physical activity may decrease the risk of breast cancer . This study , however , had limited statistical power to detect small effects OBJECTIVE To evaluate the association between physical activity and all case mortality  in postmenopausal women . DESIGN Prospect i ve cohort study with 7 years of follow-up through December 31 , 1992 . SETTING AND PARTICIPANTS Subjects were 40417 postmenopausal Iowa women , aged 55 to 69 years at baseline in 1986 .  Physical activity was assessed by mailed question naire . MAIN OUTCOME MEASURE  All-cause mortality ( n=2260 ) . RESULTS After adjustment for potential confounders and excluding women who reported having cancer or heart disease and those who died in the first 3 years of follow-up , women who reported regular physical activity were at significantly reduced risk of death during follow-up compared with women who did not ( relative risk [ RR ] , 0.77 ; 95 % confidence interval [ CI ] , 0.66 - 0.90 ) . Increasing frequency of moderate physical activity was associated with reduced risk of death during follow-up ( from rarely or never engaging in activity to activity at least 4 times per week , RRs , 1.0 [ referent ] , 0.76 , 0.70 , and 0.62 ; P value for trend<.001 ) . A similar pattern was seen for vigorous physical activity ( corresponding RRs , 1.0 , 0.89 , 0.74 , and 0.57 ; Pvalue for trend=.06 ) . Reduced risks of death with increased physical activity were evident for cardiovascular diseases ( n=729 ) and respiratory illnesses ( n=147 ) . Women who engaged only in moderate but not vigorous physical activity also benefited , with moderate activity as infrequently as once per week demonstrating a reduced mortality risk of 0.78 ( 95 % CI , 0.64 - 0.96 ) . CONCLUSIONS These results demonstrate a grade d , inverse association between physical activity and all-cause mortality  in postmenopausal women . These findings strengthen the confidence that population recommendations to engage in regular physical activity are applicable to postmenopausal women BACKGROUND Physical activity has been related to reduced risk of osteoporotic hip fractures , but the evidence among men is weak . OBJECTIVE To determine the association between baseline leisure physical activity and future risk of osteoporotic hip fracture in men . METHODS At baseline in 1975 our prospect i ve study cohort included 3,262 men who were 44 years or older and did not have chronic disease restricting their ability to exercise .  At baseline , physical activity was assessed by a question naire . Hip fractures were followed for 21 years , or from the age of 50 years for subjects who were initially younger than 50 years . RESULTS The hazard ratio of osteoporotic hip fracture , adjusted for other possible predictors ( height , body mass index , baseline diseases , smoking , use of alcohol , work-related physical activity , and occupational group ) , in men participating in vigorous physical activity compared with men not participating was 0.38 ( 95 % confidence interval , 0.16 - 0.91 ) ( P = .03 ) . CONCLUSION These results provide further evidence that there is an inverse association between baseline physical activity  and future hip fracture risk among men Background — Higher levels of physical activity are associated with fewer cardiovascular disease  (  CVD ) events . Although the precise mechanisms underlying this inverse association are unclear , differences in several cardiovascular risk factors may mediate this effect . Methods and Results — In a prospect i ve study of 27 055 apparently healthy women , we measured baseline levels of hemoglobin A1c , traditional lipids ( total , low-density lipoprotein , and high-density lipoprotein cholesterol ) , novel lipids [ lipoprotein(a ) and apolipoprotein A1 and B-100 ] , creatinine , homocysteine , and inflammatory/hemostatic biomarkers  ( high-sensitivity C-reactive protein , fibrinogen , soluble intracellular adhesion molecule-1 ) and used women 's self-reported physical activity , weight , height , hypertension , and diabetes . Mean follow-up was 10.9±1.6 years , and 979 incident CVD events occurred . The risk of CVD decreased linearly with higher levels of activity ( P for linear trend < 0.001 ) . Using the reference group of < 200 kcal/wk of activity yielded age- and treatment-adjusted relative risk reductions associated with 200 to 599 , 600 to 1499 , and ≥1500 kcal/wk of 27 % , 32 % , and 41 % , respectively . Differences in known risk factors explained a large proportion ( 59.0 % ) of the observed inverse association . When sets of risk factors were examined , inflammatory/hemostatic biomarkers made the largest contribution to lower risk ( 32.6 % ) , followed by blood pressure ( 27.1 % ) . Novel lipids contributed less to CVD risk reduction compared with traditional lipids ( 15.5 % and 19.1 % , respectively ) . Smaller contributions were attributed to body mass index ( 10.1 % ) and hemoglobin A1c/diabetes ( 8.9 % ) , whereas homocysteine and creatinine had negligible effects ( < 1 % ) . Conclusions — The inverse association between  physical activity  and CVD risk is mediated in substantial part by known risk factors , particularly inflammatory/hemostatic factors and blood pressure OBJECTIVE : To assess the value of broadly based customary physical activity scores , derived from a question naire inventory , in predicting 10 year mortality  among elderly people . DESIGN : A 10 year survival analysis of participants in the first wave of the Nottingham longitudinal study of activity and ageing who , in face to face interviews in 1985 , provided detailed information on customary physical activity , health , and lifestyle . SETTING : Urban and suburban Nottingham PARTICIPANTS : A total of 1042 people aged 65 years and over r and omly sample d from general practitioner records . MAIN RESULTS : On the basis of factor scores derived from the interview question naire , activity levels were grade d as " high " , " intermediate " , or " low " . In Cox regression models controlling for age , health status , and cigarette smoking at the time of the activity assessment , these gradings were significantly related to 10 year survival . Relative to the " high " activity groups , the risk of dying was significantly increased in both the " intermediate " ( hazard ratio ( HR ) 1.53 ; 95 % CI 1.12 , 2.09 ) and " low " ( HR 2.07 ; 95 % CI 1.53 , 2.79 ) groups for women , and in the " low " group ( HR 1.59 ; 95 % CI 1.12 , 2.25 ) for men ( p < 0.01 throughout ) . CONCLUSION : Since the survival model controlled for age , health status , and cigarette smoking , it is unlikely that the activity gradings used here are simple proxies for physical health . It is concluded , therefore , that within the elderly population , recall based survey assessment s covering a wide range of customary or habitual physical activities , can provide indices showing both cross sectional utility and predictive validity Abstract — Prospect i ve studies on physical activity in relation to the risk for hypertension are scant , particularly in women . This study aim ed at finding out whether regular physical activity can reduce the risk of hypertension in both men and women , and in subjects with and without overweight . We prospect ively followed 8302 Finnish men and 9139 women aged 25 to 64 years without a history of antihypertensive drug use , coronary heart disease , stroke , and heart failure at baseline . Both single and joint associations of physical activity and body mass index with the risk of hypertension were examined using Cox proportional hazard models . During a mean followup of 11 years , there were 1600 incident cases of drug-treated hypertension . Multivariate-adjusted hazards ratios of hypertension associated with light , moderate , and high physical activity were 1.00 , 0.63 , and 0.59 in men ( Ptrend<0.001 ) , and 1.00 , 0.82 , and 0.71 in women ( Ptrend=0.005 ) , respectively . This association persisted both in subjects who were overweight and in those who were not . Multivariate-adjusted hazards ratios of hypertension based at different levels of body mass index ( < 25 , 25 to 29.9 , and ≥30 ) were 1.00 , 1.18 , and 1.66 for men ( Ptrend<0.001 ) , and 1.00 , 1.24 , and 1.32 for women ( Ptrend=0.007 ) , respectively . Further adjustment for baseline systolic blood pressure did not affect the protective effect associated with physical activity , but it weakened markedly the association between body mass index and hypertension . The present study indicates that regular physical activity and weight control  can reduce the risk of hypertension . The protective effect of physical activity was observed in both sexes regardless of the level of obesity OBJECTIVE To examine the independent associations of vigorous ( > or = 6 resting metabolic rate [ MET ] score ) and nonvigorous ( < 6 MET score ) physical activity with longevity . DESIGN Prospect i ve cohort study , following up men from 1962 or 1966 through 1988 . SETTING / PARTICIPANTS Subjects were Harvard University alumni , without self-reported , physician-diagnosed cardiovascular disease , cancer , or chronic obstructive pulmonary disease ( n = 17,321 ) . Men with a mean age of 46 years reported their physical activities on question naires at baseline . MAIN OUTCOME MEASURE  All-cause mortality  ( 3728 deaths ) . RESULTS Total energy expenditure and energy expenditure from vigorous activities , but not energy expenditure from nonvigorous activities , related inversely to mortality . After adjustment for potential confounders , the relative risks of dying associated with increasing quintiles of total energy expenditure were 1.00 ( referent ) , 0.94 , 0.95 , 0.91 and 0.91 , respectively ( P [ trend ] < .05 ) . The relative risks of dying associated with less than 630 , 630 to less than 1680 , 1680 to less than 3150 , 3150 to less than 6300 , and 6300 or more kJ/wk expended on vigorous activities were 1.00 ( referent ) , 0.88 , 0.92 , 0.87 , and 0.87 , respectively ( P [ trend ] = .007 ) . Corresponding relative risks for energy expended on nonvigorous activities were 1.00 ( referent ) , 0.89 , 1.00 , 0.98 , and 0.92 , respectively ( P [ trend ] = .36 ) . Analyses of vigorous and nonvigorous activities were mutually adjusted . Among men who reported only vigorous activities ( 259 deaths ) , we observed decreasing age-st and ardized mortality rates with increasing activity ( P = .05 ) ; among men who reported only nonvigorous activities ( 380 deaths ) , no trend was apparent ( P = .99 ) . CONCLUSIONS These data demonstrate a grade d inverse relationship between total physical activity and mortality . Furthermore , vigorous activities but not nonvigorous activities were associated with longevity . These findings pertain only to all-cause mortality ;  nonvigorous exercise has been shown to benefit other aspects of health BACKGROUND The positive health effects of physical activity are well known . However , there are few studies of the association between different levels of physical activity and all-cause mortality among elderly people . METHODS A national r and om sample of 3206 women and men aged > /=65 were interviewed in 1988 and 1989 and followed until December 31 , 2000 , for all-cause mortality .  Cox regression was used to analyze the association between five different levels of physical activity and all-cause mortality , after adjustment for gender , age , education , smoking habits , body mass index , diabetes , hypertension , and self-rated health . All analyses were conducted in 2003 . RESULTS For elderly people who were physically active occasionally , the risk of all-cause mortality was 28 % lower than for those who were physically inactive ( hazard ratio [HR]=0.72 ; confidence interval [CI]=0.64 - 0.81 ) , after adjustment for all explanatory variables . For those who were physically active once a week , the risk of all-cause mortality was 40 % lower than for those who were physically inactive ( HR=0.60 ; CI=0.50 - 0.71 ) . For those who were physically active more frequently , the reduction in all-cause mortality risk was about the same as for those who were physically active once a week . Diabetes , hypertension , and daily smoking were , as expected , significant risk factors for all-cause mortality . CONCLUSIONS Physical activity , even occasionally , decreases the risk of all-cause mortality among elderly people . Preventive re sources among the elderly should include moderate exercise such as walking There is good evidence that physical activity reduces the risk for cardiovascular disease ( 1 - 6 ) , possibly in part by lowering blood pressure ( 7 ) . Although mild or moderate physical activity , such as brisk walking , is a recommended part of the treatment protocol for persons with hypertension ( 8 , 9 ) , it is not known whether mild physical activity , especially walking , reduces the risk for hypertension . With few exceptions , epidemiologic studies of physical activity and hypertension have been cross-sectional rather than prospect i ve . Physical activity was inversely related to blood pressure in cross-sectional and controlled studies ( 7 ) , and in two prospect i ve studies ( 10 , 11 ) , vigorous exercise was inversely related to the subsequent risk for hypertension . Physicians in Japan usually advise their patients to walk to work as often as they can , and indeed , for middle-aged working Japanese men , the journey to and from work seems to be the main source of exercise . We prospect ively examined the relation of mild physical activity , especially walking to work , and leisure-time physical activity to the risk for hypertension during 6 to 16 years of observation . Methods The Osaka Health Survey The Osaka Health Survey is an ongoing cohort study of risk factors for chronic diseases , including hypertension and diabetes . Study participants are male employees of a gas company in Osaka , Japan . Japanese law requires all employers to conduct annual health screenings for all employees . For the purpose s of the Osaka Health Survey , in addition to these annual screenings , all employees 35 years of age or older undergo more detailed biennial clinical examinations and complete question naires on health-related behaviors , including exercise . Study Sample Between 1981 and 1990 , 7979 Japanese men 35 to 63 years of age at entry who had sedentary occupations were enrolled in the study . We excluded 1875 men because they had physician-diagnosed hypertension , borderline hypertension ( systolic blood pressure 140 and < 160 mm Hg , diastolic blood pressure 90 and < 95 mm Hg , or both in men without a history of hypertension ) , diabetes , or impaired glucose tolerance ( fasting plasma glucose level 6.1 mmol/L [ 110 mg/dL ] and < 7.8 mmol/L [ < 140 mg/dL ] in men with no history of diabetes ) at entry . The study sample ultimately consisted of 6104 men . Data Collection and Measurements The biennial clinical examination consisted of a medical history ; a physical examination ; blood pressure measurement ; anthropometric measurements ; measurement of the fasting plasma glucose level ; and surveys of health-related behaviors , such as physical activity , smoking , and daily alcohol consumption . Trained nurses took all measurements . Participants were asked to fast for 12 hours and to avoid smoking and heavy physical activity for more than 2 hours before the examination . After a 5-minute rest in a quiet room , a st and ard mercury sphygmomanometer was used to measure systolic and diastolic blood pressures in the right arm while the participant was seated . Pressure was measured twice , at an interval of a few minutes . Anthropometric measurements included height and body weight , which were measured while the participant was wearing light clothing without shoes . Body mass index was calculated as the weight in kilograms divided by the height in meters squared . The question naire completed by each participant elicited information on leisure-time physical activity , the duration of the walk to work , the nature of the participant 's occupation , and the level of activity involved . Leisure-time physical activity was defined as physical activity unrelated to the participant 's work . Questions about leisure-time physical activity were as follows : Do you engage in any regular physical exercise , such as jogging , bicycling , swimming , and tennis , long enough to work up a sweat ( lasting 30 minutes or more ) ? If yes , how many times per week ? What exercise is this ? The questions about regular physical exercise have been vali date d as a measure of physical exercise ( 12 - 15 ) . In the analysis , participants were classified as engaging in regular physical exercise at least once per week or less than once per week . They were also classified into one of three categories of exercise frequency : 0 ( less than once per week ) , once per week , or two or more times per week . The question about the duration of the walk to work was How long does it take you to walk to this office ? Occupational activity was scored as 1 if the participant 's work was mostly sedentary and 2 if he worked outside or if the job required a lot of lifting and walking . In the present study , we excluded all participants who reported a score of 2 for their occupational activities . Questions about alcohol intake included items about the type of alcoholic beverage , the weekly frequency of alcohol consumption , and the usual amount consumed daily . Alcohol intake was converted to total alcohol consumption ( in milliliters of ethanol per day ) by using st and ard Japanese tables . Current and past smoking habits were classified according to the type and quantity of cigarettes smoked daily . Participants were classified as current smokers , past smokers , or nonsmokers . Hypertension was also diagnosed during the biennial study clinical examinations . All participants underwent medical screening by a physician at least once annually , and hypertension was also diagnosed by the physicians . Hypertension was defined by using World Health Organization criteria as physician-diagnosed hypertension ( systolic blood pressure 160 mm Hg , diastolic blood pressure 95 mm Hg , or both ) or use of antihypertensive medication ( 16 ) . Statistical Analysis Age-adjusted mean values and relevant population characteristics were computed for the duration of the walk to work by using analysis of covariance for continuous variables and the direct method for categorical variables . For each participant , person-years of follow-up were counted from the date at study entry to the date of diagnosis of hypertension or 1 April 1997 , whichever came first . The rate of follow-up was 94 % of the total potential person-years of follow-up . Multivariate Cox proportional-hazards regression models were used to evaluate the simultaneous effects of the duration of the walk to work , the frequency of leisure-time physical activity , age , body mass index  , daily alcohol consumption , smoking status , and fasting plasma glucose level . Baseline systolic and diastolic blood pressure were not included in our primary analyses because they could presumably be in the causal pathway between the exposures ( such as physical activity , age , body mass index , and alcohol consumption ) and risk for hypertension . However , we included systolic and diastolic blood pressure in further models to assess the effect of physical activity on the risk for hypertension independent of their effects on systolic and diastolic blood pressure . The linear trends in risks were evaluated by entering indicators for each categorical level of exposure or by using the median value for each category . As a reference category , we used men with the lowest level of physical activity . To address the potential misclassification of leisure-time physical activity over time , additional analyses were performed on the basis of the data at both study entry ( 1981 to 1990 ) and the examination done 4 years after ( 1985 to 1994 ) each participant was enrolled . We also performed analyses that excluded participants who developed hypertension between study entry ( 1981 to 1990 ) and the third examination done 4 years later ( 1985 to 1994 ) . We calculated the 95 % CI for each relative risk ( 17 ) , and all P values are two-tailed . Statistical analyses were performed by using the SPSS 7.5J software package ( SPSS , Inc. , Chicago , Illinois ) . We estimated the number needed to walk , a value analogous to the number needed to treat . The number needed to treat for a given therapy is the reciprocal of the absolute risk reduction for that treatment ( 18 ) . A 95 % CI for the number needed to treat is obtained simply by taking reciprocals of the values defining the 95 % CI of the absolute risk reduction ( 19 ) . In our study , the number needed to walk was defined as the number of men who would have to adopt walking to avoid a single case of hypertension . The number needed to treat must always be based on an outcome for a specific period of time ( 20 ) ; thus , in estimating the number needed to walk , we chose an observation period of 10 years between study entry ( 1981 to 1986 ) and the examination done 10 years after ( 1991 to 1996 ) each participant was enrolled . Role of the Funding Source The funding agencies did not participate in the collection , analysis , or interpretation of data presented in this report or in the decision to su bmi t the manuscript for publication . Results Of the 6104 men eligible for this study between 1981 and 1990 , we excluded 87 men who did not undergo medical check-ups during the follow-up period . The study sample for analysis consisted of 6017 men . During the 59 784 person-years of follow-up between 1981 and 1997 , 626 men developed hypertension . As the duration of the walk to work increased , body weight and the body mass index decreased ( P for trend=0.037 and 0.035 , respectively ) ( Table 1 ) . We identified no significant relation between the duration of the walk to work and the levels of leisure-time physical activity ( P for trend=0.062 ) . Table 1 . Baseline Characteristics according to Duration of the Walk to Work Duration of the Walk to Work The duration of the walk to work was associated with a decreased risk for incident hypertension ( Table 2 ) . After adjustment for age , body mass index , daily alcohol consumption , smoking status , frequency of leisure-time physical activity , systolic blood pressure , diastolic blood pressure , and fasting plasma glucose level , the relative risk for hypertension was 0.71 ( 95 % CI , 0.52 to 0.97 ) in men whose walk to work lasted 21 minutes or more compared with those The aim of this study was to describe changes in grip strength over a follow-up period of approximately 27 yr and to study the associations of rate of strength decline with weight change and chronic conditions . The data are from the Honolulu Heart Program , a prospect i ve population -based study established in 1965 . Participants at exam 1 were 8,006 men ( ages 45 - 68 yr ) who were of Japanese ancestry and living in Hawaii . At follow-up , 3,741 men ( age range , 71 - 96 yr ) participated . Those who died before the follow-up showed significantly lower grip-strength values at baseline than did the survivors . The average annualized strength change among the survivors was -1.0 % . Steeper decline ( > 1.5%/yr ) was associated with older age at baseline , greater weight decrease , and chronic conditions such as stroke , diabetes , arthritis , coronary heart disease , and chronic obstructive pulmonary disease . The risk factors for having very low h and -grip strength at follow-up , here termed grip-strength disability ( < /=21 kg , the lowest 10th percentile ) , were largely same as those for steep strength decline . However , the age-adjusted correlation between baseline and follow-up strength was strong ( r = 0.557 , P < 0.001 ) ; i.e. , those who showed greater grip strength at baseline were also likely to do so 27 yr later . Consequently , those in the lowest grip-strength tertile at baseline had about eight times greater risk of grip-strength disability than those in the highest tertile because of their lower reserve of strength . In old age , maintenance of optimal body mass may help prevent steep strength decrease and poor absolute strength Physical activity improves health , and current recommendations encourage daily exercise . However , little is known about any health benefits associated with infrequent bouts of exercise ( e.g. , 1 - 2 episodes/week ) that generate the recommended energy expenditure . The authors conducted a prospect i ve cohort study among 8,421 men ( mean age , 66 years ) in the Harvard Alumni Health Study , without major chronic diseases , who provided details about physical activity on mailed question naires in 1988 and 1993 . Men were classified as " sedentary " ( expending < 500 kcal/week ) , " insufficiently active " ( 500 - 999 kcal/week ) , " weekend warriors " ( > /=1,000 kcal/week from sports/recreation 1 - 2 times/week ) , or " regularly active " ( all others expending > /=1,000  kcal/week ) . Between 1988 and 1997 , 1,234 men died . The multivariate relative risks for mortality among the sedentary , insufficiently active , weekend warriors , and regularly active men were 1.00 ( referent ) , 0.75 ( 95 % confidence interval ( CI ) : 0.62 , 0.91 ) , 0.85 ( 95 % CI : 0.65 , 1.11 ) , and 0.64 ( 95 % CI : 0.55 , 0.73 ) , respectively . In stratified analysis , among men without major risk factors , weekend warriors had a lower risk of dying , compared with sedentary men ( relative risk = 0.41 , 95 % CI : 0.21 , 0.81 ) . This was not seen among men with at least one major risk factor ( corresponding relative risk = 1.02 , 95 % CI : 0.75 , 1.38 ) . These results suggest that regular physical activity generating 1,000 kcal/week or more should be recommended for lowering mortality rates . However , among those with no major risk factors , even 1 - 2 episodes/week generating 1,000 kcal/week or more can postpone mortality BACKGROUND In several epidemiological studies , breast cancer risk has been reduced among women who reported high levels of occupational or leisure-time physical activity .  We used data from a population -based case control study to evaluate the effect of occupational physical activity on breast cancer risk . METHODS Two hundred-thirty three incident cases of breast cancer and 670 controls or their next of kin were interviewed for information on breast cancer risk factors and a complete job history .  Physical activity level of jobs were classified using a Department of Labor rating scheme . We calculated adjusted odds ratios for light and medium/heavy activity jobs compared to sedentary jobs . RESULTS Odds ratios for women who held medium/heavy jobs for less than 10 years and more than ten years were , respectively , 0.7 ( 95 % CI = 0.4,1.3 ) and 1.7 ( 95 % CI = 0.9,3.3 ) . CONCLUSIONS In these data there was no evidence that holding a job of medium/heavy activity reduced breast cancer risk . The study was limited by misclassification inherent in the occupational exposure scheme and by the lack of information on leisure time physical activity . The modest risk increase for subjects holding a medium/heavy job for at least 10 years probably represents either confounding or r and om variation BACKGROUND Physical activity is associated with low mortality in men , but little is known about the association in women , different age groups , and everyday activity . OBJECTIVE To evaluate the relationship between levels of physical activity during work , leisure time , cycling to work , and sports participation and all-cause mortality . DESIGN Prospect i ve study to assess different types of physical activity associated with risk of mortality during follow-up after the subsequent examination . Mean follow-up from examination was 14.5 years . SETTING Copenhagen University Hospital , Copenhagen , Denmark . PARTICIPANTS Participants were 13,375 women and 17,265 men , 20 to 93 years of age , who were r and omly selected .  Physical activity was assessed by self-report , and health status , including  blood pressure , total cholesterol level , triglyceride levels , body mass index , smoking , and educational level  , was evaluated . MAIN OUTCOME MEASURE All-cause mortality . RESULTS A total of 2,881 women and 5,668 men died . Compared with the sedentary , age- and sex-adjusted mortality rates in leisure time physical activity groups 2 to 4 were 0.68 ( 95 % confidence interval , 0.64 - 0.71 ) , 0.61 ( 95 % confidence interval , 0.57 - 0.66 ) , and 0.53 ( 95 % confidence interval , 0.41 - 0.68 ) , respectively , with no difference between sexes and age groups . Within the moderately and highly active persons , sports participants experienced only half the mortality of non participants . Bicycling to work decreased risk of mortality in approximately 40 % after multivariate adjustment , including leisure time physical activity . CONCLUSIONS Leisure time physical activity was inversely associated with  all-cause mortality in both men and women in all age groups . Benefit was found from moderate leisure time physical activity , with further benefit from sports activity and bicycling as transportation Background The purpose was to conduct systematic review s of the relationship between physical activity of healthy community-dwelling older ( > 65 years ) adults and outcomes of  functional limitations , disability , or loss of independence .  Methods Prospect i ve cohort studies with an outcome related to functional independence or to cognitive function  were search ed , as well as exercise training interventions that reported a functional outcome . Electronic data base search strategies were used to identify citations which were screened ( title and abstract ) for inclusion . Included articles were review ed to complete st and ardized data extraction tables , and assess study quality . An established system of assessing the level and grade of evidence for recommendations was employed . Results Sixty-six studies met inclusion criteria for the relationship between physical activity and functional independence , and 34 were included with a cognitive function outcome . Greater physical activity of an aerobic nature ( categorized by a variety of methods ) was associated with higher functional status ( expressed by a host of outcome measures ) in older age . For functional independence , moderate ( and high ) levels of physical activity appeared effective in conferring a reduced risk ( odds ratio ~0.5 ) of functional limitations or disability . Limitation in higher level performance outcomes was reduced ( odds ratio ~0.5 ) with vigorous ( or high ) activity with an apparent dose-response of moderate through to high activity . Exercise training interventions ( including aerobic and resistance ) of older adults showed improvement in physiological and functional measures , and suggestion of longer-term reduction in incidence of mobility disability . A relatively high level of physical activity was related to better cognitive function and reduced risk of developing dementia ; however , there were mixed results of the effects of exercise interventions on cognitive function indices . Conclusions There is a consistency of findings across studies and a range of outcome measures related to functional independence ; regular aerobic activity and short-term exercise programmes confer a reduced risk of functional limitations and disability in older age . Although a precise characterization of a minimal or effective physical activity dose to maintain functional independence is difficult , it appears moderate to higher levels of activity are effective and there may be a threshold of at least moderate activity for significant outcomes Objective To prospect ively examine the association between physical activity and the risk of developing colorectal cancer in a large population -based cohort study of Japanese men and women , and to investigate whether the effects of physical activity on colorectal cancer risk differ by sex and subsite . Methods We analyzed data from a population -based cohort of 65,022 subjects . A total of 486 incident colorectal cancers ( 154 proximal colon , 166 distal colon and 149 rectal cancers ) was identified during 6 years of follow-up . Results We observed a significant inverse association between physical activity  and the risk of developing colorectal cancer , particularly colon cancer , among men . Relative to men in the lowest level of metabolic equivalent ( MET ) hours per day , those in the highest level had a RR of 0.69 ( 95 % CI = 0.49–0.97 ) . A significant decrease in risk of colorectal cancer was associated with increasing MET hours per day among men . This inverse association was essentially limited to colon cancer . A significant decrease in risk with increasing MET-hour score was observed predominantly for proximal colon cancer among men . In contrast , no significant decrease was seen among women . Conclusion These findings suggest that physical activity may prevent colon cancer among Japanese men BACKGROUND Physical activity has been found to be associated with decreased risk of breast cancer in postmenopausal women in the majority of epidemiologic studies , but the association is inconsistent in premenopausal women . METHODS We studied the effect of physical activity at various ages on the incidence of breast cancer in 99,504 women from 30 to 49 years of age at enrollment in the Women 's Lifestyle and Health Study , a prospect i ve population -based cohort study in Norway and Sweden .  Physical activity level on an ordinal scale at age 14 , age 30 , and age at enrollment , participation in competitive sports , as well as information on other covariates was obtained using a self-administered question naire . Complete follow-up with data on incident invasive breast cancer and mortality was collected by linkage to national registries . The relation between physical activity  and time to breast cancer development was assessed using Cox proportional hazard models , controlling for potential confounders . RESULTS During an average 9.1 years of follow-up , there were 1,166 incident breast cancer cases . The mean age of the women was 41 years at enrollment , and the mean age at breast cancer diagnosis was 48 years . Compared to inactive women , women with higher levels of physical activity at enrollment had a similar risk of incident breast cancer ( adjusted relative risk , 1.24 for vigorous activity compared with no activity ; 95 % CI , 0.85 - 1.82 ) . Physical activity at age 30 or at age 14 also did not afford any significant protection from breast cancer , nor did a consistently high level of activity from younger ages to enrollment . CONCLUSIONS We did not find evidence of a protective effect of physical activity on breast cancer risk in this group of primarily premenopausal women We set out to examine the long-term effect of work-related and leisure time physical activity on risk of death from  coronary heart disease ( CHD ) and other causes . Data were obtained from a large prospect i ve population study of 7142 participant men aged 47 to 55 years at baseline in 1970 - 1973 and without symptomatic CHD . Data on physical activity at work and at leisure were assessed by way of a question naire . After 20 years follow-up men with physically dem and ing work had a slightly higher mortality from all causes , but not from CHD . The association with all-cause mortality disappeared after controlling for smoking , occupational class , and alcohol abuse . Men who were physically active during leisure time had a lower risk of death from CHD , cancer , and all causes . After controlling for smoking , diastolic blood pressure , serum cholesterol , body mass index , diabetes alcohol abuse , and low occupational class , the most active men had a relative risk ( RR ) of dying from CHD of 0.72 ( 0.56 - 0.92 95 % CI ) and of all causes of 0.70 ( 0.61 - 0.80 95 % CI ) . The adjusted relative risk for cancer death was of borderline significance . Noncardiovascular deaths other than cancer showed a strong relationship with low physical activity in the present study that remained after controlling for smoking , alcohol abuse , and other factors ( adjusted RR 0.55 ( 0.42 - 0.73 95 % CI ) ) . The protective effect of CHD and on mortality was present after excluding the first 8 years of follow-up , and at all levels of other risk factors , such as smoking , diastolic blood pressure , serum cholesterol , and body mass index . In conclusion , this long-term study demonstrates the protective effect of  leisure time physical activity on CHD death , cancer death , and on death from all causes . The effect on coronary death and on death from all causes was independent of other risk factors BACKGROUND Increased physical activity has been hypothesized to prevent breast cancer , largely by reducing cumulative lifetime exposure to circulating ovarian hormones . However , epidemiologic findings are inconsistent , and there is no consensus on the best way to quantify physical activity . We thus examined this issue in a large cohort of women , using several different measures of adult physical activity . METHODS We analyzed data from the Nurses ' Health Study , a prospect i ve study of women aged 30 to 55 years in 1976 . In 1980 and on subsequent surveys , women were asked about the average number of hours per week spent in various moderate and vigorous recreational physical activity during the past year . We computed a " baseline-only " ( 1980 ) measure of hours per week of physical activity , as well as a cumulative average measure that used up date d reports on physical activity . During 16 years of follow-up , we identified 3137 cases of invasive breast cancer ( 1036 premenopausal and 2101 postmenopausal women ) . Data were analyzed by use of multivariate pooled logistic regression to produce relative risks of breast cancer , and the associated confidence intervals . RESULTS Women who were more physically active in adulthood had a lower risk of breast cancer than those who were less physically active . Comparing those who reported engaging in moderate or vigorous physical activity for 7 or more hours per week with those who engaged in such physical activity for less than 1 hour per week , the relative risk was 0.82 ( 95 % confidence interval , 0.70 - 0.97 ) , using the cumulative average updating . The dose-response trend was statistically significant ( P = .004 ) . Using the baseline-only measure of physical activity produced slightly weaker relative risks . CONCLUSION These results contribute to the body of evidence suggesting that higher levels of adult physical activity afford modest protection against breast cancer BACKGROUND To evaluate the hypothesis that physical activity independently predicts type 2 diabetes  risk in postmenopausal African-American , Hispanic , Asian , and Caucasian women . METHODS We prospect ively evaluated the relationship between incident type 2 diabetes , walking , and total physical activity  at baseline in the Women 's Health Initiative Observational Study . Baseline data were collected between September 1994 and December 1998 ; incident diabetes was identified through August 2002 . Hazard ratios for self-reported diabetes adjusted for body mass index ( BMI ) and other variables were evaluated across categories of physical activity in Caucasian , African-American , Hispanic , and Asian/Pacific Isl and er women . RESULTS Incident diabetes was reported by 2.2 % of Caucasian , 6.2 % of African-American , 4.5 % of Hispanic , 3 % of Asian , and 5.7 % of American Indian women ( p < 0.0001 across ethnic groups ) during 458,018 woman-years of follow-up . Among Caucasian women ,  walking  ( multivariate-adjusted hazard ratios 1.00 , 0.85 , 0.87 , 0.75 , 0.74 ; p < 0.001 for trend across exercise quintiles ) and  total physical activity score ( hazard ratios 1.00 , 0.88 , 0.74 , 0.80 , 0.67 ; p = 0.002 ) demonstrated a strong inverse relationship with diabetes risk . In BMI -adjusted models , African-American women in higher physical activity categories were less likely to develop diabetes than women in the lowest physical activity category . After adjusting for age and multiple risk factors , however , no significant association between  physical activity and diabetes risk was apparent for African-American , Hispanic , or Asian women . CONCLUSIONS These findings suggest a stronger and more independent association of physical inactivity with development of  diabetes in Caucasian women than in minority women , but could also be explained by less precise risk estimates in minority women or the role of chance BACKGROUND About two-thirds of Canadians are physically inactive . As a risk factor for several chronic diseases , physical inactivity can potentially be a substantial public health burden . We estimated the direct health care costs attributable to  physical inactivity  in Canada , the number of lives lost prematurely each year that are attributable to a sedentary lifestyle and the effect that a reduction of 10 % in inactivity levels ( a Canadian objective for 2003 ) could have on reducing direct health care costs . METHODS We calculated summary relative risk ( RR ) estimates from prospect i ve longitudinal studies of the effects of physical inactivity on coronary artery disease , stroke , colon cancer , breast cancer , type 2 diabetes mellitus and osteoporosis . We then computed the population -attributable fraction ( PAF ) for each illness from the summary RR and the prevalence of physical inactivity ( i.e. , 62 % ) and applied the PAF to the total direct health care expenditures for 1999 and to the number of deaths in 1995 associated with each disease to determine the health care costs and lives lost prematurely that were directly attributable to physical inactivity . RESULTS About $ 2.1 billion , or 2.5 % of the total direct health care costs in Canada , were attributable to physical inactivity in 1999 . A sensitivity analysis ( simultaneously varying each of the health care costs and PAF by + /- 20 % ) indicated that the costs could be as low as $ 1.4 billion and as high as $ 3.1 billion . About 21,000 lives were lost prematurely in 1995 because of inactivity . A 10 % reduction in the prevalence of physical inactivity has the potential to reduce direct health care expenditures by $ 150 million a year . INTERPRETATION Physical inactivity represents an important public health burden in Canada . Even modest reductions in inactivity levels could result in substantial cost savings Abstract Objectives : To examine any association between social , productive , and physical activity and 13 year survival in older people . Design : Prospect i ve cohort study with annual mortality follow up . Activity and other measures were assessed by structured interviews at baseline in the participants ' homes Proportional hazards models were used to model survival from time of initial interview . Setting : City of New Haven , Connecticut , United States . Participants : 2761 men and women from a r and om population sample of 2812 people aged 65 and older . Main outcome measure : Mortality from all causes during 13 years of follow up . Results : All three types of activity were independently associated with survival after age , sex , race/ethnicity , marital status , income , body mass index , smoking , functional disability , and history of cancer , diabetes , stroke , and myocardial infa rct ion were controlled for . Conclusions : Social and productive activities that involve little or no enhancement of fitness lower the risk of all cause mortality as much as fitness activities do . This suggests that in addition to increased cardiopulmonary fitness , activity may confer survival benefits through psychosocial pathways . Social and productive activities that require less physical exertion may complement exercise programmes and may constitute alternative interventions for frail elderly people . Key messages Little is known about predictors of survival among elderly people Physical activity is clearly good for health , but the potential benefits of social activities have not been studied Social and productive activities are as effective as fitness activities in lowering the risk of death Enhanced social activities may help to increase the quality and length of Background and Purpose The objective of this study was to determine the risk factors of stroke incidence and mortality . Methods Our data are based on a prospect i ve cohort study of men aged 40 to 49 years after 12 years of follow-up . Results In age-adjusted Cox proportional-hazards regression analysis of 14 403 healthy men , diastolic blood pressure was a stronger predictor for stroke incidence and mortality than systolic blood pressure . Smoking was a stronger predictor of mortality than of incidence . However , there was no dose-response relation among smokers by increased cigarette consumption . Total serum cholesterol was a significant ( P < .05 ) risk factor for stroke mortality and of borderline significance ( P=.08 ) for stroke incidence . Increased physical activity  at leisure was associated with reduced stroke incidence but not mortality . The myocardial infa rct ion risk score comprising systolic blood pressure , total serum cholesterol , and daily cigarette smoking was a strong predictor of mortality and incidence . Body mass index , triglycerides , blood glucose , and physical activity at work were not found to be risk factors for stroke . Conclusions Reduction of blood pressure , cessation of smoking , lowered cholesterol  , and increased physical activity at leisure  are individual measures to reduce the risk of stroke The Canadian Heart Health Surveys are cross-sectional , population -based cardiovascular disease risk factor surveys that took place in each of the 10 Canadian provinces between 1986 and 1992 . Hypertension awareness , treatment , and control status are examined . Of 23,129 r and omly selected , noninstitutionalized respondents aged 18 to 74 years , 85 % had four  blood pressure ( BP ) measurements taken under st and ardized conditions  , two at home during a home interview and two at a following clinic visit . The mean of all available measurements was used to determine hypertension status . Estimates are weighted and represent population values . Only 2 % of respondents had never had their BP checked , and 73 % had had their BP checked in the last 12 months . A systolic or diastolic BP > or = 140/90 mm Hg was found in 22 % of participants ( 26 % of men , 18 % of women ) , representing 4.1 million Canadians . Overall , 16 % of participants were treated and controlled ; 23 % were treated and not controlled ; 19 % were not treated and not controlled ; and 42 % were unaware of their hypertension ( 47 % of men and 35 % of women ) . Among hypertensives 18 to 34 years old , 64 % of men and 19 % of women were unaware of their hypertension . Among treated and not controlled hypertensives 63 % had a mean systolic BP > or = 150 mm Hg , and 29 % a diastolic BP > or = 95 mm Hg , suggesting that an important number of Canadians treated for hypertension are still at increased risk . Despite frequent interactions with the health care system , too many Canadians are still not well controlled or are unaware of their hypertension Background Physical activity is associated with a decreased risk of coronary heart disease ( CHD ) .  However , it is unclear whether the duration of exercise episodes is important : Are accumulated shorter sessions as predictive of decreased risk as longer sessions if the same amount of energy is expended ? Methods and Results In the Harvard Alumni Health Study , we prospect ively followed 7307 Harvard University alumni ( mean age 66.1 years ) from 1988 through 1993 . At baseline , men reported their  walking , stair climbing , and participation in sports or recreational activities .  For each of the latter activities , they also reported the frequency and average duration per episode . During follow-up , 482 men developed CHD .  In age-adjusted analysis , a longer duration of exercise episodes predicted lower CHD risk ( P trend=0.04 ) . However , after total energy expended on physical activity and potential confounders was accounted for , duration no longer had an independent effect on CHD risk ( P trend=0.25 ) ; that is , longer sessions of exercise did not have a different effect on risk compared with shorter sessions , as long as the total energy expended was similar . In contrast , higher levels of total energy expenditure significantly predicted decreased CHD risk in both age-adjusted ( P trend=0.009 ) and multivariate ( P trend=0.046 ) analyses . Conclusions These data clearly indicate that physical activity is associated with decreased CHD risk . Furthermore , they lend some support to recent recommendations that allow for the accumulation of shorter sessions of physical activity , as opposed to requiring 1 longer , continuous session of exercise . This may provide some impetus for those sedentary to become more active BACKGROUND AND PURPOSE Physiologically , it appears plausible for physical activity to decrease stroke risk ; however , epidemiological studies have produced mixed findings . Furthermore , few studies have examined specific kinds and intensities of activities . The purpose of this study was to examine the association between physical activity , including its various components ( walking , climbing stairs , participation in sports and recreational activities ) , and stroke risk . METHODS This was a prospect i ve cohort study of 11 130 Harvard University alumni ( mean age , 58 years ) without cardiovascular disease and cancer at baseline . Men reported their walking , stair climbing , and participation in sports or recreation on baseline question naires in 1977 . Stroke occurrence was assessed with another question naire in 1988 . Death certificates were obtained for decedents through 1990 to determine strokes not previously reported ( total strokes=378 ) . We used Cox proportional hazards regression to estimate the relative risks and 95 % CIs for stroke occurrence associated with physical activity . RESULTS After adjustment for age , smoking , alcohol intake , and early parental death , the relative risks of stroke associated with < 1000 , 1000 to 1999 , 2000 to 2999 , 3000 to 3999 , and > /=4000 kcal/wk of energy expenditure at baseline were 1.00 ( referent ) , 0.76 ( 95 % CI , 0.59 to 0.98 ) , 0.54 ( 0.38 to 0 . 76 ) , 0.78 ( 0.53 to 1.15 ) , and 0.82 ( 0.58 to 1.14 ) , respectively ; P=0 . 05 for linear trend . Walking > /=20 km/wk was associated with significantly lower risk , independent of other physical activity components . Climbing stairs and activities of at least moderate intensity ( > /=4.5 METs , or multiples of resting metabolic rate ) each showed U-shaped relations to stroke risk , with the risk being significantly lower at the nadir of the curve . Light intensity activities ( < 4.5 METs ) , however , were unrelated to stroke risk . CONCLUSIONS Physical activity is associated with decreased stroke risk in men . A decreased risk was observed at energy expenditures of 1000 to 1999 kcal/wk , with further risk decrement seen at 2000 to 2999 kcal/wk but not beyond . Confirmation of the U-shaped relation observed in these data requires similar observations in other population CONTEXT Individual contributions of obesity and physical fitness ( physical activity and functional capacity ) to risk of coronary heart disease in women remain unclear . OBJECTIVE To investigate the relationships of measures of obesity ( body mass index [ BMI ] , waist circumference , waist-hip ratio , and waist-height ratio ) and physical fitness ( self-reported Duke Activity Status Index [ DASI ] and Postmenopausal Estrogen-Progestin Intervention question naire [ PEPI-Q ] scores ) with coronary artery disease ( CAD ) risk factors , angiographic CAD , and adverse cardiovascular ( CV ) events in women evaluated for suspected myocardial ischemia . DESIGN , SETTING , AND PARTICIPANTS The National Heart , Lung , and Blood Institute-sponsored Women 's Ischemia Syndrome Evaluation ( WISE ) is a multicenter prospect i ve cohort study . From 1996 - 2000 , 936 women were enrolled at 4 US academic medical centers at the time of clinical ly indicated coronary angiography and then assessed ( mean follow-up , 3.9 [ SD , 1.8 ] years ) for adverse outcomes . MAIN OUTCOME MEASURES Prevalence of obstructive CAD ( any angiographic stenosis > or=50 % ) and incidence of adverse CV events ( all-cause death or hospitalization for nonfatal myocardial infa rct ion , stroke , congestive heart failure , unstable angina , or other vascular events ) during follow-up . RESULTS Of 906 women ( mean age , 58 [ SD , 12 ] years ) with complete data , 19 % were of nonwhite race , 76 % were overweight ( BMI > or=25 ) , 70 % had low functional capacity ( DASI scores < 25 , equivalent to < or=7 metabolic equivalents [ METs ] ) , and 39 % had obstructive CAD . During follow-up , 337 ( 38 % ) women had a first adverse event , 118 ( 13 % ) had a major adverse event , and 68 ( 8 % ) died . Overweight women were more likely than normal weight women to have CAD risk factors , but neither BMI nor abdominal obesity measures were significantly associated with obstructive CAD or adverse CV events after adjusting for other risk factors ( P = .05 to.88 ) . Conversely , women with lower DASI scores were significantly more likely to have CAD risk factors and obstructive CAD ( 44 % vs 26 % , P<.001 ) at baseline , and each 1-MET increase in DASI score was independently associated with an 8 % ( hazard ratio , 0.92 ; 95 % confidence interval , 0.85 - 0.99 ; P = .02 ) decrease in risk of major adverse CV events during follow-up . CONCLUSIONS Among women undergoing coronary angiography for suspected ischemia , higher self-reported physical fitness scores were independently associated with fewer CAD risk factors , less angiographic CAD , and lower risk for adverse CV events . Measures of obesity were not independently associated with these outcomes BACKGROUND Long-term physical activity may affect breast cancer risk . Few prospect i ve studies have evaluated in situ or invasive breast cancer risk , or breast cancer receptor subtypes , in relation to long-term activity . METHODS We examined the association between recreational physical activity and risk of invasive and in situ breast cancer in the California Teachers Study , a cohort of women established in 1995 - 1996 . Of 110 599 women aged 20 to 79 years with no history of breast cancer followed up through December 31 , 2002 , 2649 were diagnosed as having incident invasive breast cancer and 593 were diagnosed as having in situ breast cancer . Information was collected at cohort entry on participation in strenuous and moderate recreational activities during successive periods from high school through the current age or age 54 years ( if older at enrollment ) and in the past 3 years . A summary measure of  long-term activity up to the current age , or age 54 years if older , was constructed for each woman . RESULTS Invasive breast cancer risk was inversely associated with long-term strenuous activity  ( > 5 vs < /=0.5 h/wk per year : relative risk , 0.80 ; 95 % confidence interval , 0.69 - 0.94 ; P trend = .02 ) , as was in situ breast cancer risk ( > 5 vs < /=0.5 h/wk per year : relative risk , 0.69 ; 95 % confidence interval , 0.48 - 0.98 ; P trend = .04 ) . Strenuous and moderate long-term activities were associated with reduced risk of ER-negative ( strenuous : P trend = .003 ; moderate : P trend = .003 ) but not ER-positive ( strenuous : P trend = .23 ; moderate : P trend = .53 ) invasive breast cancer . CONCLUSION These results support a protective role of strenuous long-term exercise activity against invasive and in situ breast cancer and suggest differing effects by hormone receptor status BACKGROUND The purpose of this study was to analyse both cross-sectional associations and how longitudinal changes in lifestyle factors from one state in 1980 - 1981 to another in 1988 - 1989 influence self-reported health status . Another aim was to estimate the hazard ratios for all-cause mortality for the changes in lifestyle factors and self-reported hypertension during the same period of time . METHOD The cross-sectional and the longitudinal analyses are based on the same simple r and om sample of 3,843 adults , aged 25 - 74 , interviewed in 1980 - 1981 and 1988 - 1989 and is part of the Swedish Annual Level-of-Living Survey . About 85 % of the respondents in the first interview participated in a second interview in 1988 - 1989 . Cross-sectional odds ratios , based on a marginal model , were estimated using the generalized estimating equations . The transitional models were analysed using unconditional logistic regression . A proportional hazard model was applied to investigate the influence of lifestyle transitions on mortality . RESULTS Physical inactivity , being a current or former smoker and obesity ( women only ) were strong risk factors for poor health either as main effects and /or combined ( interactions ) . There was a strong interaction between physical activity and smoking , and for women , also between body mass index ( BMI ) and physical activity . Smoking , physically inactive and obese women had about a ten times higher risk of poor health status than non-smoking , physically active , and normal-weight women . The corresponding risk for men was about five times higher . Physically active , but smoking and obese individuals showed only moderately increased risks for poor health status . The transitional model showed that those who were physically inactive in 1980 - 1981 , but did exercise in 1988 - 1989 , improved their health after adjustments for sociodemographic and other lifestyle factors . Continuing to smoke or being physically inactive or having hypertension at both points in time were all associated with higher hazard ratios for all-cause mortality ( 1.6 , 1.9 and 1.8 , respectively ) than those who reported that they were in good status at both points in time . CONCLUSIONS We found that physical activity protects against poor health irrespective of an increased BMI and smoking . The major clinical implication s are the long-st and ing benefits of physical activity and not smoking BACKGROUND Whether national physical activity recommendations are related to mortality benefit is incompletely understood . METHODS We prospect ively examined physical activity guidelines in relation to mortality  among 252,925 women and men aged 50 to 71 years in the National Institutes of Health-American Association of Retired Persons ( NIH-AARP ) Diet and Health Study .  Physical activity was assessed using 2 self-administered baseline question naires . RESULTS During 1,265,347 person-years of follow-up , 7,900 participants died . Compared with being inactive , achievement of activity levels that approximate the recommendations for moderate activity ( at least 30 minutes on most days of the week ) or vigorous exercise ( at least 20 minutes 3 times per week ) was associated with a 27 % ( relative risk [ RR ] , 0.73 ; 95 % confidence interval [ CI ] , 0.68 - 0.78 ) and 32 % ( RR , 0.68 ; 95 % CI , 0.64 - 0.73 ) decreased mortality risk , respectively . Physical activity reflective of meeting both recommendations was related to substantially decreased mortality risk overall ( RR , 0.50 ; 95 % CI , 0.46 - 0.54 ) and in subgroups , including smokers ( RR , 0.48 ; 95 % CI , 0.44 - 0.53 ) and nonsmokers ( RR , 0.54 ; 95 % CI , 0.45 - 0.64 ) , normal weight ( RR , 0.45 ; 95 % CI , 0.39 - 0.52 ) and overweight or obese individuals ( RR , 0.48 ; 95 % CI , 0.44 - 0.54 ) , and those with 2 h/d ( RR , 0.53 ; 95 % CI , 0.44 - 0.63 ) and more than 2 h/d of television or video watching ( RR , 0.50 ; 95 % CI , 0.45 - 0.55 ) . Engaging in physical activity at less than recommended levels was also related to reduced mortality risk ( RR , 0.81 ; 95 % CI , 0.76 - 0.86 ) . CONCLUSIONS Following physical activity guidelines is associated with lower risk of death . Mortality benefit may also be achieved by engaging in less than recommended activity levels OBJECTIVE To investigate the association between cardiorespiratory fitness and the incidence of type 2 diabetes among Japanese men . RESEARCH DESIGN AND METHODS This prospect i ve cohort study was conducted in 4747 nondiabetic Japanese men , aged 20 - 40 years at baseline , enrolled in 1985 with follow-up to June 1999 .  Cardiorespiratory fitness was measured using a cycle ergometer test , and Vo(2max )  was estimated . During a 14-year follow-up , 280 men developed type 2 diabetes .  RESULTS The age-adjusted relative risks of developing type 2 diabetes across quartiles of cardiorespiratory fitness ( lowest to highest ) were 1.0 ( referent ) , 0.56 ( 95 % CI 0.42 - 0.75 ) , 0.35 ( 0.25 - 0.50 ) , and 0.25 ( 0.17 - 0.37 ) ( for trend , P < 0.001 ) . After further adjustment for BMI , systolic blood pressure , family history of diabetes , smoking status , and alcohol intake , the association between type 2 diabetes risk and cardiorespiratory fitness was attenuated but remained significant ( 1.0 , 0.78 , 0.63 , and 0.56 , respectively ; for trend , P = 0.001 ) . CONCLUSIONS These results indicate that a low cardiorespiratory fitness level is an important risk factor for incidence of type 2 diabetes among Japanese men BACKGROUND Scientific evidence shows that physically active people are protected from developing acute myocardial infa rct ion ( MI ) . However , the effect of the intensity , duration and type of activity remains unclear . OBJECTIVE To evaluate the relation between physical activity and MI , according to different intensity levels and types , we conducted a community-based case-control study , based on the Risk of Coronary Heart Disease ( EPIcardis ) study . METHODS We evaluated 381 consecutive cases of first MI ( 297 males ; 84 females ) and 726 community controls ( 310 males ; 416 females ) , older than 39 years , selected by r and om digit dialing ( 70 % participation rate among the controls ) . Data were collected using a structured question naire . For evaluation of physical activity , the question naire assessed all professional and leisure-time activities , specifying the type of exercise and the time spent in each activity . Activities were grouped according to intensity using energy expenditure at rest as the baseline ( 1.0 MET ) : very light ( 1.5 MET ) , light ( 2.5 MET ) , moderate ( 5.0 MET ) and strenuous ( 7.0 MET ) . Odds ratios ( OR ) and 95 % confidence intervals ( 95 % CI ) were calculated using unconditional logistic regression and separate models for each sex . RESULTS Among men , after adjusting for age , education , family history of MI , energy intake and smoking , the OR ( 95 % CI ) were 0.51 ( 0.29 - 0.91 ) , 0.36 ( 0.19 - 0.68 ) , 0.53 ( 0.30 - 0.93 ) , and 0.68 ( 0.39 - 1.20 ) , for increasing quintiles of activity ( p for trend = 0.199 ) . Among women , after adjusting for the same variables plus parity and menopausal status , the OR ( 95 % CI ) were 0.51 ( 0.25 - 1.03 ) , 0.37 ( 0.17 - 0.83 ) , and 0.34 ( 0.14 - 0.83 ) , for increasing quartiles of activity ( p for trend = 0.006 ) . We found a protective effect of leisure-time physical activity  in men ( p for trend < 0.001 ) and in women ( p for trend = 0.038 ) . In men , the U-shaped effect described for total physical activity was also found for occupational activities . CONCLUSIONS The present study supports an independent protective effect of leisure-time physical activity , but not of occupational activities , for risk of myocardial infa rct ion OBJECTIVE To determine whether self-reported physical activity predicts a decreased rate of coronary heart disease ( CHD ) and all-cause mortalities in middle-aged men when rates are adjusted for known confounders . DESIGN Cohort Analytic Study of Israeli government employees in 1963 . SUBJECTS Eight thous and four hundred sixty-three Israeli male government employees , aged 40 years or older , representing six areas of birth , excluding those with known cardiovascular disease in either 1963 or 1965 , from an original cohort of 10,059 . MAIN OUTCOME MEASURE Comparison of rates of death due to CHD and all causes , determined from death certificates in 21 years of follow-up , for subjects with different baseline levels of self-reported leisure-time and work-related physical activities measured in 1965 . RESULTS Self-reported leisure-time but not work-related physical activity was inversely related to both CHD ( adjusted relative risk , 0.79 ; 95 % confidence interval , 0.66 to 0.95 ) and all-cause mortalities ( adjusted relative risk , 0.91 ; 95 % confidence interval , 0.83 to 0.99 ) . Most of the apparent benefit accrued was from light physical activity on less than a daily basis . These inverse relationships persisted after adjustment for age , systolic blood pressure , cigarette smoking , total and high-density lipoprotein cholesterol levels , body mass index , psychosocial factors , and other potential confounders . CONCLUSION Baseline levels of self-reported leisure-time physical activity predicted a decreased rate of CHD and all-cause mortalities in employed middle-aged Israeli men followed up prospect ively for 21 years BACKGROUND Type 2 diabetes mellitus is increasingly common , primarily because of increases in the prevalence of a sedentary lifestyle and obesity . Whether type 2 diabetes can be prevented by interventions that affect the lifestyles of subjects at high risk for the disease is not known . METHODS We r and omly assigned 522 middle-aged , overweight subjects ( 172 men and 350 women ; mean age , 55 years ; mean body-mass index [ weight in kilograms divided by the square of the height in meters ] , 31 ) with impaired glucose tolerance to either the intervention group or the control group . Each subject in the intervention group received individualized counseling aim ed at reducing weight , total intake of fat , and intake of saturated fat and increasing intake of fiber and physical activity . An oral glucose-tolerance test was performed annually ; the diagnosis of diabetes was confirmed by a second test . The mean duration of follow-up was 3.2 years . RESULTS The mean ( + /-SD ) amount of weight lost between base line and the end of year 1 was 4.2+/-5.1 kg in the intervention group and 0.8+/-3.7 kg in the control group ; the net loss by the end of year 2 was 3.5+/-5.5 kg in the intervention group and 0.8+/-4.4 kg in the control group ( P<0.001 for both comparisons between the groups ) . The cumulative incidence of diabetes after four years was 11 percent ( 95 percent confidence interval , 6 to 15 percent ) in the intervention group and 23 percent ( 95 percent confidence interval , 17 to 29 percent ) in the control group . During the trial , the risk of diabetes was reduced by 58 percent ( P<0.001 ) in the intervention group . The reduction in the incidence of diabetes was directly associated with changes in lifestyle . CONCLUSIONS Type 2 diabetes can be prevented by changes in the lifestyles of high-risk subjects BACKGROUND The epidemiologic observation that physical activity reduces the risk for hypertension has only been made for white men who self-reported hypertension . This study examined physical activity and clinical ly determined incident hypertension in black and white men and women of the Atherosclerosis Risk in Communities ( ARIC ) Study . METHODS ARIC is a population -based prospect i ve study with four U.S. clinic centers . The present analyses included 7,459 black and white adults 45 - 65 years of age . Hypertension  ( systolic/diastolic blood pressure > /= 140/90 mm Hg ) was defined by blood pressure measured by a r and om-zero device or medication use .  Physical activity  was assessed with the  Baecke question  naire . RESULTS After adjustment for age , baseline blood pressure , ARIC center , education , body mass index , waist-hip ratio , parental history of hypertension , cigarette smoking , alcohol consumption , and diet , white men in the highest quartile of leisure activity ( primarily cycling and walking ) had a 34 % lower odds of developing hypertension over 6 years compared to the least active ( OR = 0.66 , 95 % CI = 0.47 - 0.94 ; P for quartile trend = 0.01 ) . Baseline activity was not associated with incident hypertension  in white women or blacks . CONCLUSIONS Leisure-time physical activity reduces the odds of  hypertension  in middle-aged white men . Additional studies in women and blacks are needed We investigated several aspects of the role of physical activity in colon and rectal cancer etiology that remain unclear in the European Prospect i ve Investigation into Nutrition and Cancer . This cohort of 413,044 men and women had 1,094 cases of colon and 599 cases of rectal cancer diagnosed during an average of 6.4 years of follow-up . We analyzed baseline data on occupational , household , and recreational activity to examine associations by type of activity , tumor subsite , body mass index ( BMI ) , and energy intake . The multivariate hazard ratio for colon cancer was 0.78 [ 95 % confidence interval ( 95 % CI ) , 0.59 - 1.03 ] among the most active participants when compared with the inactive , with evidence of a dose-response effect ( Ptrend = 0.04 ) . For right-sided colon tumors , the risk was 0.65 ( 95 % CI , 0.43 - 1.00 ) in the highest quartile of activity with evidence of a linear trend ( Ptrend = 0.004 ) . Active participants with a BMI under 25 had a risk of 0.63 ( 95 % CI , 0.39 - 1.01 ) for colon cancer compared with the inactive . Finally , an interaction between BMI and activity ( Pinteraction = 0.03 ) was observed for right-sided colon cancers ; among moderately active and active participants with a BMI under 25 , a risk of 0.38 ( 95 % CI , 0.21 - 0.68 ) was found as compared with inactive participants with BMI > 30 . No comparable decreased risks were observed for rectal cancer for any type of physical activity for any subgroup analyses or interactions considered . We found that physical activity  reduced colon cancer risk , specifically for right-sided tumors and for lean participants , but not rectal cancer . ( Cancer Epidemiol Biomarkers Prev 2006;15(12):2398–407 BACKGROUND Physical inactivity and high body mass index ( weight in kilograms divided by height in square meters ) have been linked to increased risk of  colon cancer .  However , none of the few prospect i ve studies in women has shown a statistically significant reduction in colon cancer incidence or mortality associated with increased leisure-time physical activity . PURPOSE In this prospect i ve study , we asked whether leisure-time physical activity , body mass index , or body fat distribution could significantly influence the risk of colon cancer in women . METHODS The participants in this study were enrolled in the Nurses ' Health Study , which began in 1976 . Every 2 years , the women provided additional personal information and information on medical risk factors and major medical events . The time spent per week at a variety of leisure-time physical activities was determined , and the time spent at each activity was multiplied by its typical energy expenditure , expressed in terms of metabolic equivalents or METs . The result ing values for each woman were added to yield an MET-hours-per-week score . Reported diagnoses of colon cancer were confirmed by review of hospital records and pathology reports . Relative risks and associated 95 % confidence intervals were calculated . RESULTS In multivariate analyses that included body mass index , women who expended more than 21 MET-hours per week on leisure-time physical activity had a relative risk of colon cancer of 0.54 ( 95 % confidence interval [ CI ] = 0.33 - 0.90 ) in comparison with women who expended less than 2 MET-hours per week . Women who had a body mass index greater than 29 kg/m2 had a relative risk of colon cancer of 1.45 ( 95 % CI = 1.02 - 2.07 ) in comparison with women who had a body mass index less than 21 kg/m2 . A tendency toward higher colon cancer risk was observed for increasing waist-to-hip ratio ( relative risk = 1.48 [ 95 % CI = 0.88 - 2.49 ] for comparison of the highest quintile ratio [ > 0.833 ] to the lowest [ < 0.728 ] ) . CONCLUSIONS AND IMPLICATION S The significant inverse association between  leisure-time physical activity  and incidence of colon cancer in women in this study is consistent with what has been found in men . Recommendations to increase physical activity and maintain lean body weight should receive greater emphasis as part of a feasible approach to the prevention of colon cancer Westernization or industrialization leads to an increase in rates of colon cancer , which is the second leading cause of malignant death in the United States [ 1 ] . Although the precise causes of colon cancer remain unclear , a diet high in red meat or animal fat and low in fruits and vegetables appears to increase the risk for this malignancy [ 2 , 3 ] . It is perhaps less well recognized that an inverse association between physical activity and risk for colon cancer has been seen in studies of occupational activity only [ 4 - 12 ] and of both job-related and recreational activity [ 13 - 23 ] . In addition , many studies have found an association between body mass and elevated risk for colon cancer in men ; this association is weaker in women [ 24 - 33 ] . The fact that the association is stronger in men suggests that the abdominal distribution of adiposity typical in men may be an important component of enhanced risk . More limited evidence suggests that height , which may be a proxy for a person 's net energy intake during childhood and adolescence , is related to a higher risk for colon cancer [ 33 - 35 ] . We examine the association between physical activity , obesity , and attained height in relation to risk for colon cancers and their precursory adenomas in a large cohort of male health professionals in the United States . Waist and hip circumferences were available for a subcohort of the study population . We address the hypotheses that physical inactivity , obesity , and height increase the risk for colon cancer and adenoma independently of each other and of diet , and that the abdominal pattern of obesity is an additional independent risk factor . Methods Study Population The Health Professionals Follow-up Study [ 36 ] was started in 1986 ; in that year , 51 529 male dentists , optometrists , osteopaths , podiatrists , pharmacists , and veterinarians in the United States between 40 and 75 years of age responded to a mailed question naire . They reported on their leisure-time physical activity ( described below ) ; current body weight ; weight at age 21 years ; height ; history of cancer and other medical conditions ; parental history of various diseases , including colorectal cancer ; and use of aspirin and other nonsteroidal anti-inflammatory medications . They also reported dietary and alcohol intake using a vali date d [ 37 , 38 ] , semi-quantitative food-frequency question naire . We mailed an optional question naire in 1987 to assess  waist and hip circumferences . In 1988 , 1990 , and 1992 , we up date d exposure information and ascertained newly diagnosed medical conditions and history of colonoscopy or sigmoidoscopy , including the indications for endoscopy : bleeding in stool , positive results from tests for occult fecal blood , abdominal pain , diarrhea or constipation , family history of colorectal cancer , routine screening without symptoms , or follow-up [ 39 ] . Most of the deaths in the cohort were reported by family members or by the postal system in response to the follow-up question naires . We also used the National Death Index to identify deaths among nonrespondents [ 40 ] . Assessment of Physical Activity The 1986 question naire included a section about mainly recreational or leisure-time physical activity . The reliability and validity of question naires design ed to assess physical activity have been investigated [ 41 - 43 ] . A question naire such as the one used in our cohort was evaluated in a cohort of U.S. nurses and was found to provide useful information [ 44 ] , and similar results were found during a similar validation study done within the Health Professionals cohort ( Chasan-Taber S. Personal communication ) . Participants reported the average time per week spent doing each of eight moderate and vigorous activities , choosing from among 10 possible responses that ranged from 0 minutes to 11 or more hours per week . The specific activities listed were walking or hiking outdoors ( including walking during golf ) ; jogging ( slower than 10 minutes/mile ) ; running ( 10 minutes/mile or faster ) ; bicycling ( including that done on a stationary machine ) ; lap swimming ; tennis , squash , or racquetball ; and calisthenics or rowing . In addition , each respondent reported the number of flights of stairs he climbed daily and his usual walking pace . The reported time spent at each activity per week was multiplied by its typical energy expenditure requirements expressed in metabolic equivalents ( METs ) [ 45 ] to yield a MET-hour score . One MET , which is the energy expended by sitting quietly , is equivalent to 3.5 mL of oxygen uptake per kilogram of body weight per minute for a 70-kg adult . For example , 1 hour per week of running contributed 10.2 MET-hours , 1 hour of tennis contributed 6 MET-hours , and 1 hour of walking at a moderate pace contributed 3.2 MET-hours . Body weight was excluded from the derivation of energy expenditure from physical activity to avoid confounding the expenditure variable by body weight . If more than one published intensity level was available for a given activity , the moderate or general MET value was chosen . An average MET value was assigned to the categories that listed more than one activity , such as rowing or calisthenics , and squash or racquetball . Assessment of Anthropometric Variables  Each man reported his current weight and height and his weight at age 21 years on the 1986 question naire . In 1987 , we mailed an optional question naire once to obtain additional exposure information , including body circumference measurements . We instructed each participant to measure ( to the nearest quarter inch ) his waist at the umbilicus and his hips at the largest circumference between the waist and thighs while st and ing and without measuring over bulky clothing [ 46 ] . We provided a tape measure and an illustration to help st and ardize the measurements . Sixty-five percent of the cohort responded . We used the Quetelet index ( kilograms/height in meters2 ) as a measure of total adiposity , waist-to-hip ratio to measure relative distribution of fat , and waist circumference to estimate total abdominal fat . Although the waist-to-hip ratio has been used more widely , waist circumference provides an estimate of absolute abdominal adiposity , the component most closely related to important metabolic abnormalities , including hyperinsulinemia , hypertension , and high triglyceride levels . To remove extraneous variation in the waist circumference because of height ( taller men tend to have larger waist circumferences due to their larger body size rather than to obesity ) , we adjusted waist for height using residual analysis [ 47 ] . We first regressed waist on height using multiple linear regression and then added the residual to the average waist size ( 37.4 inches ) for a man of average height ( 70 inches ) to convert this measure back to the initial scale . This conversion created for each man a st and ardized waist circumference unconfounded by height . We evaluated the precision of self-reported anthropometric measures among 123 cohort members who were part of a dietary validation study [ 46 ] . Trained technicians paid the sub study participants two visits , approximately 6 months apart , to measure current weight and waist and hip circumferences . The Pearson correlation between self-report and the average of the technicians ' two measurements was 0.97 for weight , 0.95 for waist circumference , 0.88 for hip circumference , and 0.69 for waist-to-hip ratio . The men 's self- measurements of their waist circumferences were 0.36 inches greater , their self- measurements of hip circumferences were 0.78 inches smaller , and their self- measurements of weight were 2.3 pounds less than the technician 's measurements . Identification of Patients with Colorectal Cancers In 1988 , 1990 , and 1992 , we asked each participant whether cancer had been diagnosed during the previous 2 years . The response rate to the follow-up question naires was 94 % through 31 January 1992 . When a participant ( or a decedent 's next-of-kin ) reported a diagnosis of cancer of the colon or rectum , we sought permission to obtain hospital records and pathology reports . A study physician , blinded to exposure information , review ed all medical records received and extracted data about histologic type , anatomic location , and stage of the cancer . Proximal colon cancers were defined as those from the cecum to and including the splenic flexure , and distal colon cancers were defined as those in the descending and sigmoid colon . We confirmed 249 new cases of colorectal adenocarcinoma ( excluding carcinoma in situ ) , 90 % by medical records and the remainder with corroborating information about diagnosis and treatment from the cohort member . Two hundred three cancers were in the colon and 46 were in the rectum . Identification of Patients with Colorectal Adenomas and Controls Because more than 90 % of the adenomas were diagnosed during endoscopic procedures for screening or for unrelated gastrointestinal conditions , we restricted the adenoma analysis to men who had had a colonoscopy or sigmoidoscopy .  This was done to reduce the potential for detection bias . Most procedures were sigmoidoscopies ; thus , we analyzed only adenomas of the distal colorectum . Although we did not examine proximal colon adenomas , this should not have biased inferences for the distal colorectum . However , different causes for proximal adenomas may exist . A total of 12 879 men who did not meet any of the exclusion criteria ( see Data Analysis ) reported having had an endoscopy between 1986 and 1992 . In 1993 , we sent a mailing to a r and om sample of 200 controls ( men who reported negative results from an endoscopy ) to confirm that they did not have adenomas . After one mailing , 140 ( 70 % ) controls granted us permission to review the medical records of their endoscopic procedure ; none had an unreported , histologically confirmed adenoma . We were able to recontact 96 % of the men who reported a diagnosis of polyp , and we received medical records in response to more than 96 % of the requests sent to medical record departments , PURPOSE Middle-aged and older women who are physically active have decreased risk of coronary heart disease ( CHD ) ; however , little is known about how physical activity during young adulthood influences activity during middle age and older , and CHD risk . We examined the relationship between 1 ) physical activity during young adulthood and middle age , and 2 ) physical activity during each time period and CHD occurring in middle age or older . METHODS Cohort study of 39,876 healthy U.S. female health professionals , age > or = 45 yr , in the Women 's Health Study .  Physical activity  was reported at baseline . Additionally ,  physical activity in high school and age 18 - 22 yr was reported on the 24-month follow-up survey . Women were followed for an average of 9 yr , after the 24-month survey , for CHD occurrence ( N = 477 ) . RESULTS Among 37,169 eligible participants at baseline , the most active women ( vigorous physical activity 10 - 12 months x yr ) during high school and age 18 - 22 yr were more than twice as likely to meet physical activity recommendations at baseline than the least active women ( no vigorous activity ) during high school and age 18 - 22 yr ( multivariate-adjusted odds ratio = 2.43 ; 95 % C.I. 2.24 , 2.63 ) . At baseline , the most active women ( > or = 1500 kcal x wk(-1 ) ) had a 39 % lower risk of CHD during follow-up than the least active ( < 200 kcal x wk(-1 ) ) ( multivariate-adjusted relative risk = 0.61 ; 95 % C.I. 0.46 , 0.81 ) . However , physical activity during young adulthood was not associated with risk of CHD occurring during middle age and older . CONCLUSION Women who are physically active during young adulthood are more likely to be active when middle-aged and older , when rates of CHD increase , and physical activity during middle-age predicts lower risk of CHD OBJECTIVES To examine the association between physical activity and the risk of incident disability , including impairment in activities of daily living ( ADLs ) and instrumental activities of daily living ( IADLs ) , in community-based older persons free of dementia . DESIGN Prospect i ve , observational cohort study . SETTING Approximately 40 retirement communities across the Chicago metropolitan area . PARTICIPANTS More than 1,000 older persons from the Rush Memory and Aging Project , an ongoing longitudinal clinical -pathological study of common chronic conditions of old age . MEASUREMENTS All participants underwent detailed annual clinical evaluations that included assessment s of  physical activity , ADLs , IADLs , and gait performance . The associations between  physical activity , mortality , and incident disability were examined using a series of Cox proportional hazards models controlled for age , sex , education , and baseline gait . RESULTS At baseline , participants spent a mean+/-st and ard deviation of 3.0+/-3.5 hours per week engaging in physical activity ( range 0 - 35 ) . In a proportional hazards model , the risk of death decreased 11 % ( hazard ratio (HR)=0.89 , 95 % confidence interval (CI)=0.83 - 0.95 ) for each additional hour of physical activity per week . For those who were not disabled at baseline , the risk of developing disability in ADLs decreased 7 % ( HR=0.93 , 95 % CI=0.88 - 0.98 ) for each additional hour of physical activity per week . Similarly , the risk of disability in IADLs decreased 7 % ( HR=0.93 , 95 % CI=0.89 - 0.99 ) for each additional hour of physical activity . CONCLUSION For community-based older persons without dementia , physical activity is associated with maintenance of functional status , including a reduced risk of developing impairment in ADLs and IADLs BACKGROUND Increased physical activity has been hypothesized to be a means of breast cancer prevention . We examined the associations between physical activity at two different times in life and breast cancer risk . METHODS We analyzed data from the Nurses ' Health Study II , a prospect i ve study of women aged 25 - 42 years in 1989 . On the baseline survey , women were asked , " While in high school and between the ages 18 and 22 years , how often did you participate in strenuous physical activity  at least twice a week ? " We averaged answers to these two questions to develop a measure of late adolescent activity . Women were also asked at baseline to report the number of hours per  week they currently spent in different nonoccupational activities . During 6 years of follow-up , we identified 372 cases of invasive breast cancer . Data were analyzed by use of multivariate pooled logistic regression to produce relative risk ( RR ) and confidence intervals ( CIs ) of being diagnosed with the disease . RESULTS Women who were more active in late adolescence were not at reduced risk of breast cancer compared with less active women . For those women who reported engaging in strenuous activity at least twice per week for 10 - 12 months per year in late adolescence , the RR of cancer , compared with those who never engaged in such activity , was 1.1 ( 95 % CI = 0.8 - 1.6 ) . Similarly , higher levels of recent nonoccupational physical activity were not associated with reduced risk of breast cancer ( RR for > or = 7 hours of activity/week relative to < 1 hour/week = 1.1 ; 95 % CI = 0.8 - 1.5 ) . CONCLUSION Our findings do not support a link between physical activity , in late adolescence or in the recent past , and breast cancer risk among young adult women BACKGROUND As epidemiological studies have become more complex , dem and s for short , easily administered measures of risk factors have increased . This study investigates whether such a measure of physical activity is associated with the risk of death from all causes and death from specific causes . METHODS A prospect i ve follow-up study of 11,090 men and women , aged 35 - 64 years , recruited from five UK general practice s who responded to a postal question naire in 1989 .  Self-reported frequency of vigorous-intensity physical activity and data on confounding factors were collected at baseline survey . Death notifications up to 31 December 2001 were provided by the Office for National Statistics . The relative risk ( and 95 % confidence interval ) of dying associated with each level of exposure to physical activity was estimated by the hazard ratio in a series of Cox regression models . RESULTS After > 10 years ' follow-up there were 825 deaths among the 10 522 subjects with no previous history of angina or myocardial infa rct ion . Participation in vigorous exercise was associated with a significantly lower risk of all-cause mortality . Similar associations were found for ischaemic heart disease and cancer mortality , although the relationships were not significant at the 5 % level . CONCLUSIONS Simple measures of self-reported vigorous physical activity are associated with the risk of future mortality , at least all-cause mortality in a somewhat selected group . Interpretation of the finding should be treated with caution due to the reliance on self-report and the possibility that residual confounding may underlie the associations . Because moderate-intensity physical activity is also beneficial to health , short physical activity question naires should include measures of such physical activity in the future OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity BACKGROUND This study analyzed the long-term effect of leisure-time physical activity on incident cases of coronary heart disease ( CHD ) among women and men . METHODS A national , r and om sample of 2,551 women and 2,645 men , aged 35 - 74 , was interviewed in 1988 and 1989 and followed until December 31 , 2000 , with respect to CHD incident cases . Women and men hospitalized for CHD 2 years before the start of the study and those who rated their general health as poor were not included in the sample .  Leisure-time physical activity  was divided into four levels according to the frequency of physical activity . The relationship between leisure-time physical activity  and CHD was studied in a Cox regression model , adjusted for sex , age , income , smoking , and BMI . RESULTS When leisure-time physical activity increased , the risk of CHD decreased . Women and men who were physically active at least twice a week had a 41 % lower risk of developing CHD than those who performed no physical activity ( hazard ratio = 0.59 , CI = 0.37 - 0.95 ) , after adjustment for all the explanatory variables . CONCLUSIONS The positive long-term effect of  leisure-time physical activity  on  CHD risk among women and men remains even after accounting for income and other important CHD risk factors Aim /hypothesisLeisure-time physical activity can reduce the risk of Type 2 diabetes , but the potential effect of different types of physical activity is still uncertain . This study is to examine the relationship of occupational , commuting and leisure-time physical activity with the incidence of Type 2 diabetes . Methods We prospect ively followed 6898 Finnish men and 7392 women of 35 to 64 years of age without a history of stroke , coronary heart disease , or diabetes at baseline . Hazards ratios of incidence of Type 2 diabetes were estimated by levels of occupational , commuting , and leisure-time physical activity . Results During a mean follow-up of 12 years , there were 373 incident cases of Type 2 diabetes . In both men and women combined , the hazards ratios of diabetes associated with light , moderate and active work were 1.00 , 0.70 and 0.74 ( p=0.020 for trend ) after adjustment for confounding factors ( age , study year , sex , systolic blood pressure , smoking , education , the two other types of physical activity and BMI ) . The multivariate-adjusted hazards ratios of diabetes with none , 1 to 29 , and more than 30 min of walking or cycling to and from work were 1.00 , 0.96 , and 0.64 ( p=0.048 for trend ) . The multivariate-adjusted hazards ratios of diabetes for low , moderate , high levels of leisure-time physical activity were 1.00 , 0.67 , and 0.61 ( p=0.001 for trend ) ; after additional adjustment for BMI , the hazards ratio was no longer significant . Conclusions /interpretationModerate and high occupational , commuting or leisure-time physical activity independently and significantly reduces risk of Type 2 diabetes among the middle-aged general population BACKGROUND The role of walking , as compared with vigorous exercise , in the prevention of cardiovascular disease remains controversial . Data for women who are members of minority racial or ethnic groups are particularly sparse . METHODS We prospect ively examined the  total physical-activity score , walking , vigorous exercise , and hours spent sitting  as predictors of the incidence of coronary events and total cardiovascular events among 73,743 postmenopausal women 50 to 79 years of age in the Women 's Health Initiative Observational Study . At base line , participants were free of diagnosed cardiovascular disease and cancer , and all participants completed detailed question naires about  physical activity . We documented 345 newly diagnosed cases of coronary heart disease and 1551 total cardiovascular events . RESULTS An increasing  physical-activity  score had a strong , grade d , inverse association with the risk of both coronary events and total cardiovascular events . There were similar findings among white women and black women . Women in increasing quintiles of energy expenditure measured in metabolic equivalents ( the MET score ) had age-adjusted relative risks of coronary events of 1.00 , 0.73 , 0.69 , 0.68 , and 0.47 , respectively ( P for trend , < 0.001 ) . In multivariate analyses , the inverse gradient between the total MET score and the risk of cardiovascular events remained strong ( adjusted relative risks for increasing quintiles , 1.00 , 0.89 , 0.81 , 0.78 , and 0.72 , respectively ; P for trend < 0.001 ) . Walking and vigorous exercise were associated with similar risk reductions , and the results did not vary substantially according to race , age , or body-mass index . A brisker walking pace and fewer hours spent sitting daily also predicted lower risk . CONCLUSIONS These prospect i ve data indicate that both walking and vigorous exercise are associated with substantial reductions in the incidence of cardiovascular events among postmenopausal women , irrespective of race or ethnic group , age , and body-mass index . Prolonged sitting predicts increased cardiovascular risk Background The purpose of this study was to describe the associations between different levels of long-term physical activity in leisure time and subsequent causes of deaths . Design The Copenhagen City Heart Study is a prospect i ve cardiovascular population study of 19 329 men and women aged 20–93 in 1976 .  Physical activity in leisure time was estimated at the examinations in 1976–78 and 1981–83 . This analysis consists of 2136 healthy men and 2758 women aged 20–79 years , with unchanged physical activity at the two examinations , and with all covariates included in the multivariate analyses : smoking , total-cholesterol , high-density lipoprotein-cholesterol , systolic blood pressure , diabetes mellitus , alcohol consumption , body mass index , education , income , and forced expiratory volume in 10.78 ( % predicted ) . Results Adjusted relative risks ( 95 % confidence interval ) for coronary heart disease were , for moderate physical activity 0.71 ( 0.51 , 0.99 ) and for high 0.56 ( 0.38 , 0.82 ) . For cancer , moderate activity 0.77 ( 0.61 , 0.97 ) and high activity 0.73 ( 0.56 , 0.95 ) and for all-cause mortality , moderate 0.78 ( 0.68 , 0.89 ) and high 0.75 ( 0.64 , 0.87 ) for both sexes combined . Using Kaplan — Meier plots we calculated gained years of expected lifetime from age 50 . Men with high physical activity  survived 6.8 years longer , and men with moderate physical activity 4.9 years longer than sedentary men . For women the figures were 6.4 and 5.5 years , respectively . Conclusion Long-term  moderate or high physical activity  was in both sexes associated with significantly lower mortality from coronary heart disease , cancer and all-causes . The same tendency was found for stroke and respiratory diseases , but the associations did not reach statistical significance . Eur J Cardiovasc Prev Rehabil 13:173–179 © 2006 The European Society of Objective : To examine the optimal intensity of leisure time physical activity ( LTPA ) to decrease the risk of all cause , cardiovascular disease ( CVD ) , and coronary heart disease ( CHD ) mortality in a population sample of middle aged British men . Design : Prospect i ve study of middle aged men with an 11 year follow up . Setting : A whole population sample of men from Caerphilly , South Wales , UK . Subjects : 1975 men aged 49–64 years without historical or clinical evidence of CHD at baseline examination . Main outcome measures : All cause , CVD , and CHD mortality . Results : Total ( cumulative ) LTPA had a grade d , significant relation with all cause , CVD , and CHD mortality but no trend with cancer deaths . When different intensities of activity were considered , light and moderate intensity LTPA had inconsistent and non-significant relations with all cause , CVD , or CHD mortality whether adjusted only for age or for other cardiovascular risk factors . In contrast a significant dose – response relation was found for heavy intensity LTPA for all cause , CVD , and CHD mortality fully adjusted for other risk factors . Conclusions : These data suggest that , in a population of men without evidence of CHD at baseline , only leisure exercise classified as heavy or vigorous was independently associated with reduced risk of premature death from CVD CONTEXT Current public health campaigns to reduce obesity and type 2 diabetes have largely focused on increasing exercise , but have paid little attention to the reduction of sedentary behaviors . OBJECTIVE To examine the relationship between various sedentary behaviors , especially prolonged television ( TV ) watching , and risk of obesity and type 2 diabetes in women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study conducted from 1992 to 1998 among women from 11 states in the Nurses ' Health Study . The obesity analysis included 50 277 women who had a body mass index ( BMI ) of less than 30 and were free from diagnosed cardiovascular disease , diabetes , or cancer and completed questions on physical activity and sedentary behaviors at baseline . The diabetes analysis included 68 497 women who at baseline were free from diagnosed diabetes mellitus , cardiovascular disease , or cancer . MAIN OUTCOME MEASURES Onset of obesity and type 2 diabetes mellitus . RESULTS During 6 years of follow-up , 3757 ( 7.5 % ) of 50 277 women who had a BMI of less than 30 in 1992 became obese ( BMI > or = 30 ) . Overall , we documented 1515 new cases of type 2 diabetes .  Time spent watching TV was positively associated with risk of obesity and type 2 diabetes . In the multivariate analyses adjusting for age , smoking , exercise levels , dietary factors , and other covariates , each 2-h/d increment in TV watching was associated with a 23 % ( 95 % confidence interval [ CI ] , 17%-30 % ) increase in obesity and a 14 % ( 95 % CI , 5%-23 % ) increase in risk of diabetes ; each 2-h/d increment in sitting at work was associated with a 5 % ( 95 % CI , 0%-10 % ) increase in obesity and a 7 % ( 95 % CI , 0%-16 % ) increase in diabetes . In contrast , st and ing or walking around at home ( 2 h/d ) was associated with a 9 % ( 95 % CI , 6%-12 % ) reduction in obesity and a 12 % ( 95 % CI , 7%-16 % ) reduction in diabetes . Each 1 hour per day of brisk walking was associated with a 24 % ( 95 % CI , 19%-29 % ) reduction in obesity and a 34 % ( 95 % CI , 27%-41 % ) reduction in diabetes . We estimated that in our cohort , 30 % ( 95 % CI , 24%-36 % ) of new cases of obesity and 43 % ( 95 % CI , 32%-52 % ) of new cases of diabetes could be prevented by adopting a relatively active lifestyle ( < 10 h/wk of TV watching and > or = 30 min/d of brisk walking ) . CONCLUSIONS Independent of exercise levels , sedentary behaviors , especially TV watching , were associated with significantly elevated risk of obesity and type 2 diabetes , whereas even light to moderate activity was associated with substantially lower risk . This study emphasizes the importance of reducing prolonged TV watching and other sedentary behaviors for preventing obesity and diabetes OBJECTIVES To compare the effectiveness of group resistance and agility-training programs in reducing fall risk in community-dwelling older women with low bone mass . DESIGN A r and omized , controlled , single-blind 25-week prospect i ve study with assessment s at baseline , midpoint , and trial completion . SETTING Community center . PARTICIPANTS Community-dwelling women aged 75 to 85 with low bone mass . INTERVENTION Participants were r and omly assigned to one of three groups : resistance training ( n=32 ) , agility training ( n=34 ) , and stretching ( sham ) exercises ( n=32 ) . The exercise classes for each study arm were held twice weekly . MEASUREMENTS The primary outcome measure was fall risk ( derived from weighted scores from tests of postural sway , reaction time , strength , proprioception , and vision ) , as measured using a Physiological Profile Assessment ( PPA ) . Secondary outcome measures were ankle dorsiflexion strength , foot reaction time , and Community Balance and Mobility Scale score . RESULTS Attendance at the exercise sessions for all three groups was excellent : resistance training ( 85.4 % ) , agility training ( 87.3 % ) , and stretching program ( 78.8 % ) . At the end of the trial , PPA fall-risk scores were reduced by 57.3 % and 47.5 % in the resistance and agility-training groups , respectively , but by only 20.2 % in the stretching group . In the resistance and agility groups , the reduction in fall risk was mediated primarily by improved postural stability , where sway was reduced by 30.6 % and 29.2 % , respectively . There were no significant differences between the groups for the secondary outcomes measures . Within the resistance-training group , reductions in sway were significantly associated with improved strength , as assessed using increased squat load used in the exercise sessions . CONCLUSION These findings support the implementation of community-based resistance and agility-training programs to reduce fall risk in older women with low bone mass . Such programs may have particular public health benefits because it has been shown that this group is at increased risk of falling and sustaining fall-related fractures CONTEXT Physical inactivity and body mass index ( BMI ) are established independent risk factors in the development of type 2 diabetes ; however , their comparative importance and joint relationship with diabetes are unclear . OBJECTIVE To examine the relative contributions and joint association of physical activity and BMI with diabetes . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study of 37 878 women free of cardiovascular disease , cancer , and diabetes with 6.9 years of mean follow-up .  Weight , height , and recreational activities were reported at study entry . Normal weight was defined as a BMI of less than 25 ; overweight , 25 to less than 30 ; and obese , 30 or higher . Active was defined as expending more than 1000 kcal on recreational activities per week . MAIN OUTCOME MEASURE Incident type 2 diabetes , defined as a new self-reported diagnosis of diabetes . RESULTS During the follow-up , 1361 cases of incident diabetes occurred . Individually , BMI and physical activity were significant predictors of incident diabetes . Compared with normal-weight individuals , the multivariate-adjusted hazard ratio ( HR ) was 3.22 ( 95 % confidence interval [ CI ] , 2.69 - 3.87 ) for overweight individuals and 9.09 ( 95 % CI , 7.62 - 10.8 ) for obese individuals . For overall activity ( kilocalories expended per week ) , compared with the least active first quartile , the multivariate-adjusted HRs were 0.91 ( 95 % CI , 0.79 - 1.06 ) for the second quartile , 0.86 ( 95 % CI , 0.74 - 1.01 ) for the third , and 0.82 ( 95 % CI , 0.70 - 0.97 ) for the fourth ( P for trend = .01 ) . In the combined analyses , overweight and obese participants , whether active or inactive , had significantly elevated risks , compared with normal-weight active individuals . The multivariate-adjusted HRs were 1.15 ( 95 % CI , 0.83 - 1.59 ) for normal-weight inactive , 3.68 ( 95 % CI , 2.63 - 5.15 ) for overweight active , 4.16 ( 95 % CI , 3.05 - 5.66 ) for overweight inactive , 11.5 ( 95 % CI , 8.34 - 15.9 ) for obese active , and 11.8 ( 95 % CI , 8.75 - 16.0 ) for obese inactive participants . CONCLUSIONS Although BMI and physical inactivity are independent predictors of incident diabetes , the magnitude of the association with BMI was greater than with physical activity in combined analyses . These findings underscore the critical importance of adiposity as a determinant of diabetes Type 2 diabetes is a common disease in industrialized countries . It is a major cause of cardiovascular disease and all-cause mortality ( 1 - 6 ) , and its prevalence has increased continuously over the past few decades ( 1 ) . The American Diabetes Association currently defines impaired fasting glucose as a fasting plasma glucose level from 6.1 to 6.9 mmol/L ( 110 to 125 mg/dL ) and type 2 diabetes as a fasting plasma glucose level of 7.0 mmol/L ( 126 mg/dL ) or more ( 1 ) . Data from several prospect i ve studies show an inverse association between physical activity and diabetes ( 7 - 13 ) . However , these studies are limited by the use of self-reporting of physical activity and presence of type 2 diabetes ( 7 - 12 ) . Self-reporting of physical activity tends to be imprecise , and type 2 diabetes is undiagnosed in about 50 % of the prevalent cases ( 14 ) . This leads to misclassification on both exposure and outcome measures ( 15 ) . These limitations may result in underestimation of the true association between sedentary habits and risk for type 2 diabetes . Impaired fasting glucose is a strong predictor of type 2 diabetes , cardiovascular disease , and other diabetic complications ( 6 , 16 - 18 ) . The underlying cause of impaired fasting glucose is unknown , and no prospect i ve study of the association between physical activity and impaired fasting glucose has been published . We examined the relation of cardiorespiratory fitness , objective ly determined by a maximal exercise test on a treadmill , to the incidence of impaired fasting glucose and type 2 diabetes . Cases of impaired fasting glucose and diabetes at baseline and follow-up were determined by using the American Diabetes Association 's current guidelines ( 1 ) . Methods Patients In our population -based prospect i ve study , we included 8633 men 30 to 79 years of age at baseline ( mean , 43.5 years ) who completed at least two medical evaluations at the Cooper Clinic in Dallas , Texas , from 1970 to 1995 . Patients come to the Cooper Clinic for preventive medical examinations and health promotion counseling . Many are sent by their employers for these services , some are referred by their personal physicians , and others are self-referred . More than 97 % of the patients are white , and most are employed in executive or professional occupations . More than 75 % are college graduates . Although study participants came from middle and upper socioeconomic strata , they were similar to other well-characterized population -based cohorts in terms of blood pressure , cholesterol level , body weight , and cardiorespiratory fitness ( 19 ) . The study was review ed and approved annually by the institutional review board at the Cooper Institute for Aerobics Research . Additional details of the study methods and population characteristics of the cohort have been published elsewhere ( 20 , 21 ) . Because clinical or sub clinical heart disease and other conditions associated with type 2 diabetes may alter the level of physical activity and thus cardiorespiratory fitness , we excluded men with an abnormal resting or exercise electrocardiogram or a history of heart attack , stroke , or cancer at the baseline clinical examination ( n=2350 ) . The baseline evaluation was performed after participants gave written informed consent for the initial medical examination and registration in the follow-up study . Examinations were done after patients had fasted for at least 12 hours and included personal and family health histories , a question naire on demographic characteristics and health habits  , a  physical examination  , an  exercise test , anthropometric measurement , electrocardiography , blood chemistry analyses , and blood pressure measurement . Technicians who followed a st and ard manual of operations administered all procedures . Impaired fasting glucose and type 2 diabetes were diagnosed according to American Diabetes Association criteria that define impaired fasting glucose as a fasting plasma glucose level of 6.1 to 6.9 mmol/L ( 110 mg/dL to 125 mg/dL ) and diabetes as a fasting plasma glucose level of 7.0 mmol/L ( 126 mg/dL ) or more ( 1 ) . Patients who did not meet these criteria but who reported a history of diabetes or current therapy with oral antidiabetic agents or insulin were also considered to have diabetes . We excluded patients who had diabetes at baseline according to any of these criteria ( n=377 ) .  Cardiorespiratory fitness was assessed with a maximal exercise test that followed a modified Balke protocol ( 22 ) . Details of treadmill speed and elevation have been described elsewhere ( 20 , 21 ) . Briefly , the test began with the patient walking on a horizontal treadmill at 88 m/min . After the first minute , the elevation increased to 2 % ; the elevation then increased 1 % each minute up to 25 minutes . For the few patients who were still able to continue , the elevation was held constant after 25 minutes and the speed was increased by 5.4 m/min until the patient reached volitional fatigue . Use of this protocol for the exercise test correlates highly ( r=0.92 ) with measured maximal oxygen uptake ( 23 ) . All patients in our study achieved at least 85 % of their age-predicted maximal heart rate ; average maximal heart rates ( SD ) in each age group were 186 11 beats/min for patients 30 to 39 years of age , 179 12 beats/min for those 40 to 49 years of age , 172 13 beats/min for those 50 to 59 years of age , and 162 17 beats/min for those 60 years of age or older .  Average maximal heart rates in each age group exceeded the age-predicted rate ( 220 beats/min age in years ) , which indicates that the exercise test can be considered maximal performance . We defined level of fitness by  total time on the treadmill  at the baseline examination , as in our previous studies ( 20 , 21 ) . Treadmill times were placed in frequency distributions for specific age groups ( 30 to 39 , 40 to 49 , 50 to 59 , or 60 or more years of age ) . The least fit 20 % of the participants in each age group were classified as low fitness , the next 40 % as moderate fitness , and the remaining 40 % as high fitness . The respective cut-points for  total treadmill time  in the low- , moderate- , and high-fitness groups were 945 seconds or less , 946 to 1259 seconds , and 1260 seconds or more for patients 30 to 39 years of age ; 849 seconds or less , 850 to 1020 seconds , and 1021 seconds or more for patients 40 to 49 years of age ; 750 seconds or less , 751 to 1035 seconds , and 1036 seconds or more for patients 50 to 59 years of age ; and 644 seconds or less , 645 to 953 seconds , and 954 seconds or more for patients 60 years of age or older . These cut-points at the 20th and 60th percentiles to define fitness levels were used in previous studies ( 20 , 21 ) and were selected before analysis for our investigation . However , we calculated these cut-points with patients in the current study , from which unhealthy persons were excluded . Therefore , they differ somewhat from the cut-points derived from the entire cohort of the Aerobics Center Longitudinal Study ( 21 ) . For some analyses , such as the models that included change in fitness from baseline to follow-up , cardiorespiratory fitness was expressed as maximal metabolic units ( metabolic equivalents [ METs ] , calculated as the working metabolic rate/resting metabolic rate ; 1 MET is equivalent to an oxygen uptake of 3.5 mL1 kg1 ) achieved on the exercise test . In other analyses , time on the treadmill was used as a continuous variable . Serum sample s were analyzed by using automated techniques in a laboratory that participates in the Centers for Disease Control and Prevention Lipid St and ardization Program . Blood pressure was measured by using auscultatory methods with a mercury sphygmomanometer . We defined high blood pressure as systolic blood pressure of at least 140 mm Hg , diastolic blood pressure of at least 90 mm Hg , or a history of hypertension . Height and weight were measured with a st and ard physician 's scale and stadiometer , and body mass index was calculated as weight in kg/height in m2 . Waist circumference was measured with a st and ard anthropometric tape . Statistical Analysis We used SAS statistical software for data analyses ( 24 ) . The incidence of impaired fasting glucose was calculated for men with normal fasting glucose at baseline , and the incidence of diabetes was based on data from all 8633 patients . For analyses with impaired fasting glucose as the outcome , we excluded 1122 men who had impaired fasting glucose at baseline and an additional 69 men who had normal fasting plasma glucose at baseline but developed diabetes during follow-up . Rates of impaired fasting glucose or diabetes were calculated by dividing the number of incident cases during the study period by the number of person-years over the same period . We defined the study period as the interval between the baseline examination and the last follow-up visit . We used logistic regression to estimate the association between dependent variables and independent variables after adjustment for possible confounding factors . We used general linear models to study the cross-sectional association of fitness level and parental history of diabetes ( 24 , 25 ) . To account for the possible cohort effect of baseline year , we examined the relation between incident cases and baseline year and found no association . We used tests for ordinal linear trend to evaluate the possible relation of higher treadmill time with risk for impaired fasting glucose or diabetes after dividing the sample into the three fitness groups . All P values are two-sided , and those less than 0.05 were considered statistically significant . Role of the Funding Source The funding agencies did not participate in the collection , analysis , or interpretation of data presented in this report or in the decision to su bmi t the manuscript for publication . Results During an average follow-up of 6.1 4.8 years ( range , 1 to 24.8 years ) that included 52 588 person-years , 593 men developed impaired fasting glucose and 149 developed diabetes . Of the men with incident diabetes , 139 ( 93 % ) were not aware of To investigate breast cancer risk in Hispanic and non-Hispanic White women , the authors conducted a population -based case-control study of New Mexican women during 1992 - 1994 using incident breast cancer cases aged 35 - 74 years and frequency-matched controls selected using r and om digit dialing .  Activity type and weekly duration of usual nonoccupational physical activity were used to calculate weekly  metabolic equivalent (MET)-hours of total and vigorous physical activity ( > or = 5 METs ) . Conditional logistic regression models were fitted to estimate the relative risk of breast cancer for levels of physical activity and to assess the difference in effects by ethnicity , body mass index , energy intake , and menopausal status . Vigorous physical activity was associated with reduced breast cancer risk in both Hispanic and non-Hispanic White women . Women in the highest category of vigorous activity had lower risk of breast cancer ( adjusted odds ratio = 0.34 , 95 % confidence interval : 0.22 , 0.51 for Hispanic ; adjusted odds ratio = 0.60 , 95 % confidence interval : 0.41 , 0.89 for non-Hispanic White women ) compared with women reporting no vigorous physical activity . Both pre- and postmenopausal Hispanic women showed decreasing risk with increasing level of activity .  Physical activity was protective only among postmenopausal non-Hispanic White women . The effects of physical activity were independent from reproductive factors , usual body mass index , body mass index at age 18 , adult weight gain , and total energy intake BACKGROUND The observation that exercise training reduces cardiovascular mortality is robust and consistent , but the amount and intensity of exercise that is required for risk reduction is not yet resolved . METHODS We studied the association between the amount and intensity of exercise and  cardiovascular mortality  in 27 143 men and 28 929 women who were free from known cardiovascular disease at the beginning of follow-up between 1984 and 1986 . The relative risk of death was calculated as the rate of death among participants within a given physical activity category compared with the rate of death in the reference category ( no physical activity ) . We used Cox regression analysis to adjust for age and other potentially confounding factors . RESULTS After 16 years ( SD 4 years ) of follow-up , 2946 men ( 10.8 % ) and 2486 women ( 8.6 % ) had died from ischaemic heart disease or stroke . A single weekly bout of exercise of high intensity reduced the risk of cardiovascular death , both in men [ relative risk ( RR ) 0.61 , 95 % confidence interval ( CI ) 0.49 - 0.75 ] , and women ( RR 0.49 , 95 % CI 0.27 - 0.89 ) , compared with those who reported no activity . There was no additional benefit from increasing the duration or the number of exercise sessions per week . The risk reduction related to  exercise  increased with increasing age in men , but not in women . CONCLUSION These results challenge the current recommendation that expenditure of at least 1000 kcal per week is required to achieve exercise-induced protection against premature cardiovascular mortality Physical activity has frequently been reported to decrease the risk of colon cancer in men , but data on the relation of physical activity to  colon cancer risk in women have generally been less consistent . To further investigate the relationship of physical activity with  colon cancer risk in women , we studied a cohort of 31,783 US women participating in the Breast Cancer Detection Demonstration Project Follow-up Study . Information on daily physical activity over the past year was ascertained using a self-administered question naire at study baseline . The Cox proportional hazards model was used to estimate relative risks ( RRs ) relating physical activity to the risk of incident colon cancer . During 270,325 person-years of follow-up , 243 colon cancer cases were identified . No association was observed between  physical activity  and the subsequent risk of colon cancer . The multivariable RRs of colon cancer across increasing quintiles of total physical activity were 1.0 , 1.45 , 1.16 , 1.27 and 1.15 ( 95 % CI : 0.76 , 1.75 ; p(trend ) = 0.77 ) . The multivariable RRs comparing women at the extremes of moderate and vigorous physical activity , respectively , were 1.07 ( 95 % CI : 0.70 , 1.62 ) and 1.10 ( 95 % CI : 0.78 , 1.55 ) . The relationship between  physical activity and colon cancer risk did not vary by anatomic subsite or across subgroups defined by age , body mass , dietary fiber intake , menopausal status , menopausal hormone use or aspirin use . The results of this large prospect i ve cohort study among women do not support the hypothesis that physical activity is related to a lower incidence of colon cancer BACKGROUND Physical activity has been advocated as an important factor in the primary prevention of non-insulin-dependent diabetes mellitus ( NIDDM ) , but information concerning the specific intensities and duration s that are protective has been unavailable . OBJECTIVE To examine prospect ively the association between self-reported levels of the intensity and duration of physical activities  , and cardiorespiratory fitness ( assessed by  respiratory gas exchange )  and incident cases of NIDDM ( assessed by the oral glucose tolerance test ) in a population -based sample of 897 middle-aged Finnish men . RESULTS After adjustment for age , baseline glucose values , body mass index , serum triglyceride levels , parental history of diabetes , and alcohol consumption , moderately intense physical activities ( > or = 5.5 metabolic units ) that were undertaken for at least a 40-minute duration per week were associated with a reduced risk of NIDDM ( odds ration [ OR ] , 0.44 ; 95 % confidence interval [ CI ] , 0.22 - 0.88 ) . Activities with less than an intensity of 5.5 metabolic units , regardless of their duration , were not protective . Cardiorespiratory fitness levels greater than 31.0 mL of oxygen per kilogram per minute were protective against NIDDM ( OR , 0.26 ; 95 % CI , 0.08 - 0.82 ) . A subgroup of men at high risk of NIDDM , because they were overweight and were hypertensive and had a positive parental history of NIDDM , who engaged in moderately intense physical activities above the 40-min/wk duration reduced their risk of NIDDM by 64 % compared with men who did not participate in such activities . CONCLUSIONS After adjustment for age , baseline glucose levels , and known risk factors , physical activities with an intensity of 5.5 metabolic units or greater and a duration of 40 minutes or greater per week protected against the development of NIDDM . These protective effects were even more pronounced in a subgroup of men who were at high risk for the development of the disease OBJECTIVE To evaluate the relationship between changes in physical fitness and  risk of mortality in men . DESIGN Prospect i ve study , with two clinical examinations ( mean interval between examinations , 4.9 years ) to assess change or lack of change in physical fitness as associated with risk of mortality during follow-up after the subsequent examination ( mean follow-up from subsequent examination , 5.1 years ) . SETTING Preventive medicine clinic . STUDY PARTICIPANTS Participants were 9777 men given two preventive medical examinations  , each of which included assessment of physical fitness by maximal exercise tests and evaluation of health status . MAIN OUTCOME MEASURES All cause ( n = 223 ) and cardiovascular disease ( n = 87 ) mortality . RESULTS The highest age-adjusted all-cause death rate was observed in men who were unfit at both examinations ( 122.0/10,000 man-years ) ; the lowest death rate was in men who were physically fit at both examinations ( 39.6/10,000 man-years ) . Men who improved from unfit to fit between the first and subsequent examinations had an age-adjusted death rate of 67.7/10,000 man-years . This is a reduction in mortality risk of 44 % ( 95 % confidence interval , 25 % to 59 % ) relative to men who remained unfit at both examinations . Improvement in fitness was associated with lower death rates after adjusting for age , health status , and other risk factors of premature mortality . For each minute increase in maximal treadmill time between examinations , there was a corresponding 7.9 % ( P = .001 ) decrease in risk of mortality . Similar results were seen when the group was stratified by health status , and for cardiovascular disease mortality . CONCLUSIONS Men who maintained or improved adequate physical fitness were less likely to die from all causes and from cardiovascular disease during follow-up than persistently unfit men . Physicians should encourage unfit men to improve their fitness by starting a physical activity program A prospect i ve cohort study of London civil servants was used to examine the relation of physical activity to various causes of death .  6,702 men aged 40 - 64 y who participated in a baseline examination between 1969 and 1970 were followed up for 25 y during which time there were 2859 deaths . The association of two measures of physical activity ( leisure time activity and usual walking pace ) with cause-specific mortality was examined . Walking pace demonstrated inverse relations with mortality from all-causes , coronary heart disease ( CHD ) , other cardiovascular disease ( CVD ) , all cancers , respiratory disease , colorectal cancer and haematopoietic cancer following adjustment for risk factors which included age , employment grade , smoking , body mass index , and forced expiratory volume ( P [trend]<0.05 for all ) . In analyses restricted to men without disease at entry , walking pace retained inverse associations with all-cause , CHD , other cardiovascular disease , and haematopoietic cancer mortality ( P [trend]<0.05 for all ) .  Leisure time activity  was also inversely associated with mortality from all-causes , CHD , other CVD , and all-cancers following adjustment for risk factors ( P [trend]<0.05 for all ) . Eliminating deaths in the first 5 and 10 y of follow-up did not greatly alter these associations . It is concluded that physical activity may confer protection against death due to some cancers , in addition to reducing cardiovascular disease risk BACKGROUND Few studies have examined the association of physical activity with coronary heart disease among women . OBJECTIVE To examine whether participation in physical activity during leisure time decreases the risk of myocardial infa rct ion in postmenopausal women . METHOD A population -based , case-control study among enrollees of the Group Health Cooperative of Puget Sound , a health maintenance organization based in Seattle , Wash. Cases were postmenopausal women who sustained an incident nonfatal myocardial infa rct ion during the period 1986 through 1991 . Controls were a r and om sample of Group Health Cooperative enrollees who were frequency matched to the cases by age and calendar year . Participation in physical activity during leisure time was assessed from a telephone interview .  A total of 268 cases and 925 controls were interviewed . RESULTS After adjustment for potential confounding factors , the odds ratios for nonfatal myocardial infa rct ion for women in the second , third , and fourth quartile of total energy expenditure , relative to women in the first quartile , were 0.52 ( 95 % confidence interval , 0.34 to 0.80 ) , 0.40 ( 95 % confidence interval , 0.26 to 0.63 ) , and 0.40 ( 95 % confidence interval , 0.25 to 0.63 ) , respectively . Similar odds ratios were associated with the energy expended in nonstrenuous leisure-time physical activity , and with walking for exercise . CONCLUSION This case-control study suggests that the risk of myocardial infa rct ion among postmenopausal women is decreased by 50 % with modest leisure-time energy expenditures , equivalent to 30 to 45 minutes of walking for exercise three times a week OBJECTIVE To examine prospect ively the association between regular exercise and the subsequent development of  non-insulin-dependent diabetes mellitus ( NIDDM ) . DESIGN Prospect i ve cohort study including 5 years of follow-up . PARTICIPANTS 21,271 US male physicians participating in the Physicians ' Health Study , aged 40 to 84 years and free of diagnosed diabetes mellitus , myocardial infa rct ion , cerebrovascular disease , and cancer at baseline . Morbidity follow-up was 99.7 % complete . MAIN OUTCOME MEASURE Incidence of NIDDM . RESULTS At baseline , information was obtained about frequency of vigorous exercise  and other risk indicators . During 105,141 person-years of follow-up , 285 new cases of NIDDM were reported . The age-adjusted incidence of NIDDM ranged from 369 cases per 100,000 person-years in men who engaged in vigorous exercise less than once weekly to 214 cases per 100,000 person-years in those exercising at least five times per week ( P , trend , less than .001 ) . Men who exercised at least once per week had an age-adjusted relative risk ( RR ) of NIDDM of 0.64 ( 95 % Cl , 0.51 to 0.82 ; P = .0003 ) compared with those who exercised less frequently . The age-adjusted RR of NIDDM decreased with increasing frequency of exercise : 0.77 for once weekly , 0.62 for two to four times per week , and 0.58 for five or more times per week ( P , trend , .0002 ) . A significant reduction in risk of NIDDM persisted after adjustment for both age and body-mass index : RR , 0.71 ( 95 % Cl , 0.56 to 0.91 ; P = .006 ) for at least once per week compared with less than once weekly , and P , trend , .009 , for increasing frequency of exercise . Further control for smoking , hypertension , and other coronary risk factors did not material ly alter these associations . The inverse relation of  exercise  to risk of NIDDM was particularly pronounced among overweight men . CONCLUSIONS Exercise appears to reduce the development of NIDDM even after adjusting for body-mass index . Increased physical activity may be a promising approach to the primary prevention of NIDDM PURPOSE The purpose of this study was to examine the long-term relationships between total physical activity and mortality from  all causes and coronary heart disease ( CHD ) in the general population . METHODS A prospect i ve design was used , following participants for 29 years , beginning in 1960 . The study population consisted of a r and omly selected sample of white male ( n = 698 ) and female ( n = 763 ) residents of Buffalo , New York with a 79.0 % participation rate and follow-up rates of 96.0 % and 90.2 % in males and females , respectively . At baseline , comprehensive information was obtained regarding participants ' usual physical activity at work and during leisure time . RESULTS As of December 31 , 1989 , three hundred and two ( 43.3 % ) men and 276 ( 41.0 % ) women died , 109 ( 15.6 % ) and 81 ( 10.6 % ) from CHD , respectively . In men , a significant interaction was found between activity and body mass index ( BMI ) for both outcomes . In women , a significant activity by age interaction was observed . In non-obese men ( BMI < 27.02 ) , activity was inversely associated with all-cause [ relative risk ( RR ) = 0.59 ; 95 % confidence interval ( CI ) , 0.39 - 0.89 ] and CHD mortality ( RR = 0.39 ; 95 % CI , 0.18 - 0.83 ) , independent from the effects of age and education . No such associations were found in obese men and increased risks could not be ruled out . Among women , younger participants ( age < 60 years ) had a significantly reduced risk of CHD death with increased activity ( RR = 0.26 ; 95 % CI , 0.07 - 0.99 ) . No other significant associations were observed . CONCLUSIONS Physical activity favorably influences mortality risks in non-obese men and younger women . Gender-specific factors should be considered for potential effect modification We have used data from a large population -based case-control study inthe United States to evaluate the effect of occupational physical activity onbreast  cancer risk . Women diagnosed with breast cancer identified from fourstate cancer registries , and controls r and omly selected from lists oflicensed drivers or Medicare beneficiaries , were interviewed by telephone forinformation on usual occupation and other factors . We classified usualoccupation into one of four categories of physical activity . After excludingsubjects for whom a strength rating could not be assigned , we had a final sample size of 4,863 cases and 6,783 controls . Using conditional logisticregression models , we calculated adjusted odds ratios ( OR ) and 95 percentconfidence intervals ( CI ) for occupations having light , medium , and heavyactivity compared with sedentary ones . Women with heavy-activity occupationshad a lower risk of breast cancer than women with sedentary jobs ( OR = 0.82,CI = 0.63 - 1.08 ) , as di d women with jobs with medium activity ( OR = 0.86 , CI= 0.77 - 0.97 ) or light activity ( OR = 0.92 , CI = 0.84 - 1.01 ) . There was asignificant decreasing trend in the ORs from sedentary to heavy work ( P = 0.007 ) . Although limited by exposure misclassification , these data areconsistent with the hypothesis that physical activity reduces the risk ofbreast cancer AIMS To investigate separately for men and women whether moderate or high leisure time physical activity , occupational physical activity , and commuting activity are associated with a reduced cardiovascular disease ( CVD ) and all-cause mortality , independent of CVD risk factors and other forms of physical activity . METHODS AND RESULTS Prospect i ve follow-up of 15,853 men and 16,824 women aged 30 - 59 years living in eastern and south-western Finl and ( median follow-up time 20 years ) .  CVD and all-cause mortality were lower ( 9 - 21 % ) in men and women ( 2 - 17 % ) who were moderately or highly physically active during leisure time . Moderate and high levels of occupational physical activity decreased CVD and all-cause mortality by 21 - 27 % in both sexes . Women spending daily 15 min or more in walking or cycling to and from work had a reduced CVD and all-cause mortality before adjustment for occupational and leisure time physical activity . Commuting activity was not associated with CVD or all-cause mortality in men . CONCLUSION Moderate and high levels of leisure time and occupational physical activity are associated with a reduced CVD and all-cause mortality among both sexes . Promoting already moderate levels of leisure time and occupational physical activity are essential to prevent premature CVD and all-cause mortality BACKGROUND The role of walking , as compared with vigorous exercise , in the prevention of coronary heart disease remains controversial , and data for women on this topic are sparse . METHODS We prospect ively examined the associations between the score for total physical activity , walking , and vigorous exercise and the incidence of coronary events among 72,488 female nurses who were 40 to 65 years old in 1986 . Participants were free of diagnosed cardiovascular disease or cancer at the time of entry and completed serial detailed question naires about physical activity . During eight years of follow-up , we documented 645 incident coronary events ( nonfatal myocardial infa rct ion or death from coronary disease ) . RESULTS There was a strong , grade d inverse association between physical activity and the risk of coronary events . As compared with women in the lowest quintile group for energy expenditure ( expressed as the metabolic-equivalent [ MET ] score ) , women in increasing quintile groups had age-adjusted relative risks of 0.77 , 0.65 , 0.54 , and 0.46 for coronary events ( P for trend < 0.001 ) . In multivariate analyses , the inverse gradient remained strong ( relative risks , 0.88 , 0.81 , 0.74 , and 0.66 for women in increasing quintile groups as compared with those in the lowest quintile group ; P for trend=0.002 ) . Walking was inversely associated with the risk of coronary events ; women in the highest quintile group for walking , who walked the equivalent of three or more hours per week at a brisk pace , had a multivariate relative risk of 0.65 ( 95 percent confidence interval , 0.47 to 0.91 ) as compared with women who walked infrequently . Regular vigorous exercise ( > or = 6 MET ) was associated with similar risk reductions ( 30 to 40 percent ) . Sedentary women who became active in middle adulthood or later had a lower risk of coronary events than their counterparts who remained sedentary . CONCLUSIONS These prospect i ve data indicate that brisk walking and vigorous exercise are associated with substantial and similar reductions in the incidence of coronary events among women BACKGROUND AND PURPOSE Few studies have reported a protective effect of physical activity on stroke in women , particularly among elderly women . This study was conducted to examine the association between different levels of leisure-time physical activity and stroke mortality in a large prospect i ve study of middle-aged and elderly women . METHODS We conducted a 10-year mortality follow-up of women aged > /=50 years , free from stroke at baseline ( n=14 101 ) , who participated in the Nord-Trondelag Health Survey in Norway during 1984 - 1986 . Main outcome measures were relative risk of stroke mortality according to increasing levels of physical activity , with the least active group used as reference . RESULTS In groups aged 50 to 69 , 70 to 79 , and 80 to 101 years , the relative risk of dying decreased with increasing physical activity , after adjustment for potentially confounding factors . In groups aged 50 to 69 and 70 to 79 years , the most active women had an adjusted relative risk of 0 . 42 ( 95 % CI , 0.24 to 0.75 ) and 0.56 ( 95 % CI , 0.36 to 0.88 ) , respectively . In the group aged 80 to 101 years , there was a consistent negative association with physical activity ;  the adjusted relative risk for the most active was 0.57 ( 95 % CI , 0.30 to 1.09 ) . CONCLUSIONS Physical activity was associated with reduced risk of death from stroke in middle-aged and elderly women . This association persisted after we excluded individuals with prevalent cardiovascular and cerebrovascular disease at baseline and women who died during the first 2 years of follow-up . These observations strengthen the evidence that physical activity should be part of a primary prevention strategy against stroke in women The purpose of this analytical review was to estimate the direct and indirect economic costs of  physical inactivity and obesity in Canada in 2001 . The relative risks of diseases associated with physical inactivity and obesity were determined from a meta- analysis of existing prospect i ve studies and applied to the health care costs of these diseases in Canada . Estimates were derived for both the direct health care expenditures and the indirect costs , which included the value of economic output lost because of illness , injury-related work disability , or premature death . The economic burden of physical inactivity was $ 5.3 billion ( $ 1.6 billion in direct costs and $ 3.7 billion in indirect costs ) while the cost associated with obesity was $ 4.3 billion ( $ 1.6 billion of direct costs and $ 2.7 billion of indirect costs ) . The total economic costs of physical inactivity and obesity represented 2.6 % and 2.2 % , respectively , of the total health care costs in Canada . The results underscore the importance of public health efforts aim ed at combating the current epidemics of physical inactivity and obesity in Canada Background : Leisure time physical activity has previously been shown to be protective against cardiovascular disease . We estimated the influence of exercise , occupational physical activity , and household work with regard to risk of acute myocardial infa rct ion ( MI ) . Special interest was focused on potential interaction among these aspects of physical activity . Method : We analyzed data from a large population -based case-control study conducted in Stockholm , Sweden , 1992–1994 . Cases comprised 1204 men and 550 women , age 45–70 years , who experienced their first MI during the study period . The controls , 1538 men and 777 women , were r and omly selected from the study base , matched on sex , age , and hospital catchment area . The results were adjusted for several potential confounding factors . Results : Exercise , walking or st and ing at work , and doing dem and ing household work were all associated with decreased risk of acute MI ; the estimated relative risks ( RRs ) ranged from 0.31 to 0.90 when all cases ( fatal and nonfatal ) were considered . In contrast , lifting or carrying at work , and an occupational workload perceived to be strenuous , were related to an increased risk of MI ( RRs ranging from 1.10–1.57 ) . We observed a synergistic benefit from exercise and walking or st and ing at work , and from household work and walking or st and ing at work . Conclusion : Aerobic physical activities such as exercise or walking at work seemed to reduce the risk of MI , whereas anaerobic activities such as heavy lifting at work were related to increased risk of MI Background —The influence of physical activity on the incidence of angina pectoris and hard coronary events ( myocardial infa rct ion and coronary deaths ) was examined in Northern Irel and and France at contrasting risk for coronary heart disease ( CHD ) and with different physical activity patterns . Methods and Results — Participants of the Prospect i ve Epidemiological Study of Myocardial Infa rct ion ( PRIME ) ( n=9758 ; age , 50 to 59 years ) , free of CHD at baseline , were followed up for 5 years : 167 hard CHD and 154 angina events were recorded .  Net energy expenditure ( EE ) as the result of physical activity was assessed by means of the MONICA Optional Study of Physical Activity Question naire ( MOSPA-Q ) .  Leisure-time physical activity EE was calculated ; subjects were also categorized as to whether they performed high-intensity leisure-time activities or walked or cycled to work . After multivariate adjustment , leisure-time physical activity EE was associated with a lower risk of hard CHD events ( P < 0.04 ) , whereas walking or cycling to work was not independently related to hard CHD events . No interaction by country was found . The beneficial effect of leisure-time physical activity  was also present among subjects who did not report high-intensity activities ( P < 0.04 ) , with similar results in France and Northern Irel and . In contrast , an increasing level of leisure-time physical activity  was associated with a higher risk of angina in both countries . Conclusions —These data indicate a beneficial effect of leisure-time physical activity EE on hard CHD incidence in middle-aged men , which could partly explain the unfavorable rate of CHD in Northern Irel and . The higher level of leisure-time activities in France could , in part , explain its lower rate of CHD BACKGROUND Type 2 diabetes affects approximately 8 percent of adults in the United States . Some risk factors -- elevated plasma glucose concentrations in the fasting state and after an oral glucose load , overweight , and a sedentary lifestyle -- are potentially reversible . We hypothesized that modifying these factors with a lifestyle-intervention program or the administration of metformin would prevent or delay the development of diabetes . METHODS We r and omly assigned 3234 nondiabetic persons with elevated fasting and post-load plasma glucose concentrations to placebo , metformin ( 850 mg twice daily ) , or a lifestyle-modification program  with the goals of at least a 7 percent weight loss and at least 150 minutes of physical activity per week . The mean age of the participants was 51 years , and the mean body-mass index ( the weight in kilograms divided by the square of the height in meters ) was 34.0 ; 68 percent were women , and 45 percent were members of minority groups . RESULTS The average follow-up was 2.8 years . The incidence of diabetes was 11.0 , 7.8 , and 4.8 cases per 100 person-years in the placebo , metformin , and lifestyle groups , respectively . The lifestyle intervention reduced the incidence by 58 percent ( 95 percent confidence interval , 48 to 66 percent ) and metformin by 31 percent ( 95 percent confidence interval , 17 to 43 percent ) , as compared with placebo ; the lifestyle intervention was significantly more effective than metformin . To prevent one case of diabetes during a period of three years , 6.9 persons would have to participate in the lifestyle-intervention program , and 13.9 would have to receive metformin . CONCLUSIONS Lifestyle changes and treatment with metformin both reduced the incidence of diabetes in persons at high risk . The lifestyle intervention was more effective than metformin Previous epidemiological studies have shown that vigorous physical activity reduces the development of type 2 diabetes ( 1–3 ) . A recommendation from the Centers for Disease Control and Prevention reported that individuals should engage in ≥30 min of moderate-intensity physical activity , such as brisk walking , on most days of the week for health promotion and disease prevention ( 4 ) ; however , it is unclear whether mild physical activity ( i.e. , walking to walk ) reduces the risk for type 2 diabetes . In the present study , we examined the relationship between walking to work  and the development of type 2 diabetes during a 4-year observational period . The Kansai Healthcare Study is an ongoing cohort investigation design ed to clarify the risk factors for cardiometabolic diseases . Between April 2000 and March 2001 , 12,647 male employees of a company in the area of Kansai , Japan , who were aged 40–55 years at entry and considered to be involved in sedentary jobs were enrolled in this study . All employees aged ≥40 years underwent annual detailed medical check-ups . The protocol for this research was review ed by the Human Subjects Review Committee at Osaka City University . For current analysis , study participants consisted of 11,073 Japanese men aged 40–55 years at entry with a fasting plasma glucose ( FPG ) < 126 mg/dl and not taking oral hypoglycemic medication or insulin . A 4-year follow-up examination after baseline was conducted between April 2004 and March 2005 . We excluded 53 men because of death and 2,016 men because of Few prospect i ve studies have assessed the relation between physical activity and diabetes . The authors examined this relation prospect ively among 6,815 Japanese-American men in the Honolulu Heart Program who were aged 45 - 68 years and initially free of diagnosed diabetes in 1965 - 1968 . A physical activity index was calculated based on time spent per day in different activity levels and a weighting factor correlated with estimated oxygen consumption . Incidence of clinical ly recognized diabetes was based on self-reported use of diabetic medication at one of two subsequent examinations . The age-adjusted 6-year cumulative incidence of diabetes decreased progressively with increasing quintile of physical activity from 73.8 to 34.3 per 1,000 ( p < 0.0001 , trend ) in all men and from 53.9 to 21.7 per 1,000 ( p < 0.0001 , trend ) among men with a non-fasting glucose level < 225 mg/dl one hour after a 50-gm load , the latter group being less likely to have unrecognized diabetes at baseline . When stratified by tertile of baseline glucose , trends in incidence across physical activity quintiles were statistically significant in the low and middle tertiles but not in the high tertile . Similar inverse trends were observed for men in the lower four quintiles of body mass index , however , these trends were weaker and not significant for men in the upper quintile of body mass index . Age-adjusted odds ratios for diabetes comparing the upper with the lower four quintiles of physical activity were 0.55 ( 95 % confidence interval ( CI ) 0.41 - 0.75 ) for all men and 0.50 ( 95 % CI 0.33 - 0.74 ) for men with glucose < 225 mg/dl . After adjustment for age , body mass index , subscapular/triceps skinfold ratio , systolic blood pressure , triglycerides , glucose , hematocrit , and parental history of diabetes , odds ratios were still statistically significant and similar in magnitude . Restriction of analyses to men who remained free of cardiovascular disease during the study period produced similar results , which suggests that inactivity due to sub clinical cardiovascular disease is unlikely to be responsible for these findings . Risk factor-adjusted odds ratios for older men ( 55 - 68 years ) demonstrated that  physical activity confers at least the same degree of protection as in younger men ( 45 - 54 years ) . These results indicate that  physical activity  is associated inversely with incident diabetes and that the beneficial effect does not appear to be mediated through improvements in other risk factors assessed in this study OBJECTIVE : To examine the association of physical activity and body mass index ( BMI ) , and their combined effect , with the risk of total , cardiovascular disease ( CVD ) and cancer mortality .  DESIGN : Prospect i ve follow-up study .SUBJECTS : In all , 22 528 men and 24 684 women aged 25–64 y at baseline having 7394 deaths during a mean follow-up of 17.7 y . MEASUREMENT : A self-administered question naire data on smoking , socioeconomic factors , physical activity and medical history , together with measured height , weight , blood pressure and serum cholesterol using st and ardized protocol . RESULT : Physically active subjects had significantly lower age-adjusted mortality from cardiovascular , cancer and all causes compared with sedentary ones . Further adjustment for smoking , systolic blood pressure , cholesterol , BMI , diabetes and education affected the results only slightly . Obese subjects ( BMI ≥30 kg/m2 ) had significantly higher cardiovascular and total mortality than the normal weight ( 18.5≤ BMI < 25 kg/m2 ) subjects . Part of increased mortality among obese subjects was mediated through obesity-related cardiovascular risk factors . BMI had an inverse association with cancer mortality among men and almost significant direct association among women . Total mortality was also increased among the lean ( BMI < 18.5 kg/m2 ) subjects . However , less than 0.3 % of deaths were attributed to low body weight , whereas in men 5.5 % and in women 17.7 % of deaths were attributed to obesity . CONCLUSION : Regular physical activity and normal weight are both important indicators for a decreased risk of mortality from all causes , CVD and cancer . Physical activity had a strong independent effect on mortality , whereas the effect of BMI was partly mediated through other obesity-related risk factors Energy restriction remains one of the most effective ways known to prevent breast cancer in animal models . However , energy intake has not been consistently associated with risk of breast cancer in humans . In a prospect i ve study , we assessed whether energy intake , body size , and physical activity each independently influence  breast cancer risk in postmenopausal women and estimated the joint effect of combinations of these individual factors . As part of the Prostate , Lung , Colorectal , and Ovarian Cancer Screening Trial , 38,660 women , ages 55 to 74 years and recruited from 10 centers in the United States during 1993 to 2001 , were r and omized to the screening arm of the trial . At baseline , the women completed a self-administered question naire , including a food frequency question naire . During follow-up from 1993 to 2003 , 764 incident breast cancer cases were ascertained . Women in the highest quartile of energy intake ( ≥2,084 kcal/d ) compared with those in the lowest quartile ( < 1,316 kcal/d ) had a significantly increased risk for breast cancer [ multivariate relative risk ( RR ) , 1.25 ; 95 % confidence interval ( 95 % CI ) , 1.02 - 1.53 ; Ptrend continuous = 0.03 ] . Current body mass index ( BMI ) was also positively and significantly associated with risk ( multivariate RR comparing > 30 kg/m2 with < 22.5 kg/m2 , 1.35 ; 95 % CI , 1.06 - 1.70 ; Ptrend = 0.01 ) . Women with ≥4 hours/wk of vigorous recreational physical activity had a significantly reduced risk of breast cancer compared with those who reported no recreational physical activity ( multivariate RR , 0.78 ; 95 % CI , 0.60 - 0.99 ; Ptrend = 0.15 ) . None of these associations with individual energy balance measures was substantially confounded by the other two measures . When we estimated the joint effect of all three variables , women with the most unfavorable energy balance ( the highest energy intake , highest BMI , and least physical activity ) had twice the risk ( RR , 2.10 ; 95 % CI , 1.27 - 3.45 ) of women with the most favorable energy balance ( the lowest energy intake , lowest BMI , and most physical activity ) . Although our estimates of absolute energy intake , based on a food frequency question naire , are imperfect , these results suggest that energy intake , in addition to BMI and physical activity may be independently associated with breast cancer risk . In addition , these three aspects of energy balance may act jointly in determining  breast cancer risk . ( Cancer Epidemiol Prev 2006;15(2):334–41 Most studies to date support a protective role of physical activity in reducing stroke risk . However , they were not able to take into account combined work and leisure activity . We prospect ively followed up 22,602 men and women aged 40–79 years , who had no history of stroke and myocardial infa rct ion at baseline , participating in the European Prospect i ve Investigation into Cancer-Norfolk . Participants were categorized into four levels of physical activity based on a vali date d self-reported question naire , which assesses combined work and leisure activities , at baseline during the period from 1993 to 1997 . Stroke incidence was ascertained by death certificate and hospital record linkage data up to 2004 , average 8.6 years of follow-up . We used the Cox proportional hazards model . There were 361 incident strokes during follow-up ( total person years = 195,092 ) . After adjusting for age , sex , systolic blood pressure , body mass index , cholesterol , history of diabetes and smoking , men and women who were physically active were less likely to have a stroke ( relative risk = 0.70 , 95 % CI : 0.49–0.99 , p = 0.024 ) compared to those who were inactive . This highlights the fact that efforts to increase physical activity  in both the work place and in leisure time should be encouraged Due to its potential effects on ovarian hormone production , physical activity has been proposed as a modifiable risk factor for breast cancer . The authors analyzed data from the American Cancer Society Cancer Prevention Study II ( CPS-II ) Nutrition Cohort to examine the association between various measures of physical activity and postmenopausal breast cancer risk . Information on physical activity was obtained in 1992 via a self-administered question naire for 72,608 postmenopausal female participants who were cancer-free . During the five year prospect i ve follow-up , 1520 incident breast cancer cases were identified among these women . Cox proportional hazards modeling was used to compute hazard rate ratios ( RR ) and to adjust for potential confounding factors including mammography . Women who were most physically active ( > 42.0 MET-h/week ) at baseline had 29 % lower incidence rates than active women with the least activity ( > 0–7.0 MET-h/week ) ( 95 % CI , 0.49–1.02 ) . The difference in risk was largest for localized breast cancer , and for women who did not use hormone replacement therapy ( HRT ) at enrollment . Our findings are consistent with other studies that show lower risk of postmenopausal breast cancer associated with regular physical activity There is convincing evidence for a decreased risk of breast cancer  with increased physical activity . Uncertainties remain , however , about the role of different types of physical activity on breast cancer risk and the potential effect modification for these associations . We used data from 218,169 premenopausal and postmenopausal women from nine European countries , ages 20 to 80 years at study entry into the European Prospect i ve Investigation into Cancer and Nutrition .  Hazard ratios ( HR ) from multivariate Cox regression models were calculated using metabolic equivalent value – based physical activity variables categorized in quartiles , adjusted for age , study center , education , body mass index , smoking , alcohol use , age at menarche , age at first pregnancy , parity , current oral contraceptive use , and hormone replacement therapy use . The physical activity assessment included recreational , household , and occupational activities . A total physical activity index was estimated based on cross-tabulation of these separate types of activity . During 6.4 years of follow-up , 3,423 incident invasive breast cancers were identified . Overall , increasing total physical activity was associated with a reduction in breast cancer risk among postmenopausal women ( Ptrend = 0.06 ) . Specifically , household activity was associated with a significantly reduced risk in postmenopausal ( HR , 0.81 ; 95 % confidence interval , 0.70 - 0.93 , highest versus the lowest quartile ; Ptrend = 0.001 ) and premenopausal ( HR , 0.71 ; 95 % confidence interval , 0.55 - 0.90 , highest versus lowest quartile ; Ptrend = 0.003 ) women . Occupational activity and recreational activity were not significantly related to breast cancer risk in both premenopausal and postmenopausal women . This study provides additional evidence for a protective effect of  physical activity  on breast cancer risk . ( Cancer Epidemiol Biomarkers Prev 2007;16(1):36–42 CONTEXT Physical activity and fitness are believed to reduce premature mortality , but whether genetic factors modify this effect is not known . OBJECTIVE To investigate leisure physical activity and mortality with respect to familial aggregation of health habits during childhood and factors that may enable some individuals to achieve higher levels of fitness . DESIGN Prospect i ve twin cohort study . SETTING Finl and . SUBJECTS In 1975 , at baseline , 7925 healthy men and 7977 healthy women of the Finnish Twin Cohort aged 25 to 64 years who responded to a question naire on physical activity habits and known predictors of mortality . Those who reported exercising at least 6 times per month with an intensity corresponding to at least vigorous walking for a mean duration of 30 minutes were classified as conditioning exercisers , those who reported no leisure physical activity were classified as sedentary , and other subjects were classified as occasional exercisers . MAIN OUTCOME MEASURES All-cause mortality and discordant deaths among same-sex twin pairs from 1977 through 1994 . RESULTS Among the entire cohort , 1253 subjects died . The hazard ratio for death adjusted for age and sex was 0.71 ( 95 % confidence interval [ CI ] , 0.62 - 0.81 ) in occasional exercisers and 0.57 ( 95 % CI , 0.45 - 0.74 ) in conditioning exercisers , compared with those who were sedentary ( Pfor trend < .001 ) . Among the twin pairs who were healthy at baseline and discordant for death ( n=434 ) , the odds ratio for death was 0.66 ( 95 % CI , 0.46 - 0.94 ) in occasional exercisers and 0.44 ( 95 % CI , 0.23 - 0.83 ) in conditioning exercisers compared with those who were sedentary ( P for trend , .005 ) . The beneficial effect of  physical activity  remained after controlling for other predictors of mortality . CONCLUSION Leisure-time physical activity is associated with reduced mortality , even after genetic and other familial factors are taken into account The potential role of physical activity in the primary prevention of  non-insulin-dependent diabetes mellitus ( NIDDM ) is largely unknown . We examined the association between regular vigorous exercise and the subsequent incidence of NIDDM in a prospect i ve cohort of 87,253 US women aged 34 - 59 years and free of diagnosed diabetes , cardiovascular disease , and cancer in 1980 . During 8 years of follow-up , we confirmed 1303 cases of NIDDM . Women who engaged in vigorous exercise at least once per week had an age-adjusted relative risk ( RR ) of NIDDM of 0.67 ( p less than 0.0001 ) compared with women who did not exercise weekly . After adjustment for body-mass index , the reduction in risk was attenuated but remained statistically significant ( RR = 0.84 , p = 0.005 ) . When analysis was restricted to the first 2 years after ascertainment of physical activity level and to symptomatic NIDDM as the outcome , age-adjusted RR of those who exercised was 0.5 , and age and body-mass index adjusted RR was 0.69 . Among women who exercised at least once per week , there was no clear dose-response gradient according to frequency of exercise . Family history of diabetes did not modify the effect of exercise , and risk reduction with exercise  was evident among both obese and nonobese women . Multivariate adjustments for age , body-mass index , family history of diabetes , and other variables did not alter the reduced risk found with exercise . Our results indicate that physical activity may be a promising approach to the primary prevention of NIDDM BACKGROUND Since falling is associated with serious morbidity among elderly people , we investigated whether the risk of falling could be reduced by modifying known risk factors . METHODS We studied 301 men and women living in the community who were at least 70 years of age and who had at least one of the following risk factors for falling : postural hypotension ; use of sedatives ; use of at least four prescription medications ; and impairment in arm or leg strength or range of motion , balance , ability to move safely from bed to chair or to the bathtub or toilet ( transfer skills ) , or gait . These subjects were given either a combination of adjustment in their medications , behavioral instructions , and exercise programs aim ed at modifying their risk factors ( intervention group , 153 subjects ) or usual health care plus social visits ( control group , 148 subjects ) . RESULTS During one year of follow-up , 35 percent of the intervention group fell , as compared with 47 percent of the control group ( P = 0.04 ) . The adjusted incidence-rate ratio for falling in the intervention group as compared with the control group was 0.69 ( 95 percent confidence interval , 0.52 to 0.90 ) . Among the subjects who had a particular risk factor at base line , a smaller percentage of those in the intervention group than of those in the control group still had the risk factor at the time of re assessment , as follows : at least four prescription medications , 63 percent versus 86 percent , P = 0.009 ; balance impairment , 21 percent versus 46 percent , P = 0.001 ; impairment in toilet-transfer skills , 49 percent versus 65 percent , P = 0.05 ; and gait impairment , 45 percent versus 62 percent , P = 0.07 . CONCLUSIONS The multiple-risk-factor intervention strategy result ed in a significant reduction in the risk of falling  among elderly persons in the community . In addition , the proportion of persons who had the targeted risk factors for falling was reduced in the intervention group , as compared with the control group . Thus , risk-factor modification may partially explain the reduction in the risk of falling OBJECTIVE : To investigate the independent associations and the possible interaction of  body mass index ( BMI ) , leisure time physical activity ( LTPA ) and perceived physical fitness and functional capability with the risk of mortality . DESIGN : Prospect i ve 16 y follow-up study .SUBJECTS : A regionally representative cohort of 35–63 -y-old Finnish men ( n=1090 ) and women ( n=1122 ) . MEASUREMENTS : All-cause , cardiovascular disease ( CVD ) and coronary heart disease ( CHD ) mortality were derived from the national census data until the end of September 1996 while the initial levels of BMI , LTPA , physical fitness and function were determined from self-administered question naires . RESULTS : After adjustment for age , marital and employment status , perceived health status , smoking and alcohol consumption , the Cox proportional hazards model showed that BMI was not associated with the risk of death among the men or the women . Compared with the most active subjects the men and women with no weekly vigorous activity had relative risks of 1.61 ( 95 % confidence interval , CI , 0.98–2.64 ) and 4.68 ( 95 % CI , 1.41–15.57 ) , respectively , for CVD mortality , and for the men there was a relative risk of 1.66 ( 95 % CI , 0.92–2.99 ) for CHD mortality . When compared with the men who perceived their fitness as better than their age-mates , the men with the ‘ worse ’ assessment had a relative risk of 3.29 ( 95 % CI , 1.80–6.02 ) for all-cause mortality and 4.37 ( 95 % CI , 1.80–10.6 ) for CVD mortality . Men with at least some difficulty in walking a distance of 2 km had a relative risk of 1.62 ( 95 % CI , 1.05–2.50 ) for all-cause mortality when compared with those who had no functional difficulties . In addition , in the comparison with subjects with no functional difficulties , the men and women who had some difficulty climbing several flights of stairs had relative risks of 1.47 ( 95 % CI , 0.97–2.23 ) and 2.39 ( 95 % CI , 1.25–4.60 ) for all-cause mortality , respectively . For CVD mortality the relative risks were 1.85 ( 95 % CI , 1.04–3.30 ) and 3.38 ( 1.22–9.41 ) , respectively . CONCLUSIONS : Although BMI did not prove to be an independent risk factor for mortality from CVD , CHD or from all causes combined , perceived physical fitness and functional capability did . An increase in LTPA seems to have a similar beneficial effect on the mortality risk of obese and nonobese men and women , and the effect also seems to be similar for fit and unfit subjects The authors prospect ively examined the influence of increased levels of physical activity on risk of stroke  in members of the Framingham Study cohort . Two separate analyses were performed , one during midlife in 1,897 men ( mean age = 49.7 years ) and 2,299 women ( mean age = 49.9 years ) and another when the cohort was older ( 1,361 men ( mean age = 63.0 ) and 1,862 women ( mean age = 63.7 ) ) . A structured question naire administered at two separate examinations was used to estimate the amount of metabolic work done during a typical 24-hour period . Physical activity was categorized into tertiles , and medium and high levels of physical activity were compared with a low level of physical activity , which was used as the referent group . Cox proportional hazards , life table , and time-dependent covariate analyses were used to examine the relation between level of physical activity  and stroke risk over a follow-up period of up to 32 years . In men , adjusted analyses revealed that increased levels of physical activity were protective . The strongest effect was obtained from an analysis involving older cohort members in the medium tertile ( risk ratio = 0.41 , 95 % confidence interval 0.24 - 0.69 ) . High levels of physical activity  did not confer an additional benefit over medium levels . Adjusted analyses showed no significant protective effect in women . These results indicate that medium and high levels of physical activity among men are protective against stroke relative to low levels OBJECTIVE To identify risk factors and preventive measures for stroke in elderly men and women . DESIGN Observational prospect i ve cohort study . SUBJECTS Women ( N = 8532 ) and men ( N = 4722 ) between the ages of 44 and 101 ( median age , 74 ) residing in a retirement community in southern California who had no previous history of stroke . METHODS Upon entering the study in 1981 , 1983 , or 1985 , study participants filled out a detailed health survey question naire about their medical history , exercise habits , intake of caffeinated beverages , alcohol , vitamins , and foods containing vitamins A or C , and history of smoking . Women also reported their use of estrogen replacement therapy . Cohort members were followed by periodic resurvey and by examination of death records through 1998 . Age-adjusted stroke incidence rates , relative risks , and 2-sided P values were calculated . RESULTS Between 1981 and 1998 , 1211 women and 773 men were hospitalized for cerebrovascular disease . In women , risk of cerebral occlusion decreased significantly with increasing duration and recency of estrogen use . Hypertension , diabetes , heart attack , and smoking were significant stroke risk factors in both women and men . Exercise reduced stroke risk in general , and antioxidant vitamin supplements decreased the risk of cerebral occlusion . CONCLUSION These results emphasize the role of lifestyle modification in the primary prevention of stroke and suggest that estrogen replacement therapy may be a potential preventive measure for women It is considered that skeletal mass in humans may respond to loading or the number of loading cycles . The aim of this study was to examine the effect of a 1 year progressive resistance training program on the bone mass of 56 postmenopausal women . Assignment was by block r and omization to one of two resistance training groups : a strength trained group ( 3 x 8 repetition maximum ) or an endurance group ( 3 x 20 repetition maximum ) . The resistance exercises were selected to stress the ipsilateral forearm and hip region . The exercising side was r and omly assigned with one side exercised while the alternate side acted as the nonexercise control .  Bone mineral density ( BMD ) was measured every 3 months at the radial forearm and four hip sites using the Hologic QDR 2000 bone densitometer . A linear regression function was fitted for each individual 's bone density results , and the slope was compared for the exercise and control side using paired t-tests . The bone mass increase with the strength regimen was significantly greater at the trochanteric hip site ( control -0.6 + /- 2.2 % , exercise 1.7 + /- 4.1 % , p < 0.01 ) , at the intertrochanteric hip site ( control -0.1 + /- 2.1 % , exercise 1.5 + /- 3.0 % , p < 0.05 ) , Ward 's triangle ( control 0.8 + /- 5.2 % , exercise 2.3 + /- 4.0 % , p < 0.05 ) , and at the ultradistal radial site ( control -1.4 + /- 2.3 % , exercise 2.4 + /- 4.3 % , p < 0.01 ) . There was no significant increase in BMD with the endurance regimen except at the radius midsite ( control -1.0 + /- 2.3 % , exercise 0.1 + /- 1.4 % , p < 0.01 ) . In both the endurance and the strength group , muscle strength , tested by a one-repetition maximum ( 1RM ) test , increased significantly for all 10 exercises ( p < 0.01 ) and to a similar degree in the two groups . In the strength group but not the endurance group there were significant correlations between the slope of the change in BMD and the percentage increase in strength as follows : trochanter with leg press ; intertrochanter with leg press ( p < 0.05 ) ; and Ward 's triangle with hip extension and hip adduction ( p < 0.05 ) . Thus these results support the notion of a site-specific response of bone to maximal loading from resistance exercise in that although the trochanter and intertrochanter bone density was elevated by the resistance exercises undertaken , there was no effect on the femoral neck value . Postmenopausal bone mass can be significantly increased by a strength regimen that uses high-load low repetitions but not by an endurance regimen that uses low-load high repetitions . We conclude that the peak load is more important than the number of loading cycles in increasing bone mass in early postmenopausal women Objective —To test the efficacy of a community based 10 week exercise intervention to reduce fall risk factors in women with osteoporosis . Methods —Static balance was measured by computerised dynamic posturography ( Equitest ) , dynamic balance by timed figure of eight run , and knee extension strength by dynamometry . Subjects were r and omised to exercise intervention ( twice weekly Osteofit classes for 10 weeks ) or control groups . Results —The outcome in 79 participants ( 39 exercise , 40 control ) who were available for measurement 10 weeks after baseline measurement is reported . After confounding factors had been controlled for , the exercise group did not make significant gains compared with their control counterparts , although there were consistent trends toward greater improvement in all three primary outcome measures . Relative to the change in control subjects , the exercise group improved by 2.3 % in static balance , 1.9 % in dynamic balance , and 13.9 % in knee extension strength . Conclusions —A 10 week community based physical activity intervention did not significantly reduce fall risk factors in women with osteoporosis . However , trends toward improvement in key independent risk factors for falling suggest that a study with greater power may show that these variables can be improved to a level that reaches statistical significance BACKGROUND We studied the relations between physical activity and changes in physical activity , all-cause mortality , and incidence of major coronary-heart-disease events in older men . METHODS In 1978 - 80 ( Q1 ) , 7735 men aged 40 - 59 were selected from general practice s in 24 British towns , and enrolled in a prospect i ve study of cardiovascular disease , which included physical activity data . In 1992 ( Q92 ) , 12 - 14 years later , 5934 of the men ( 91 % of available survivors , mean age 63 years ) gave further information on physical activity and were then followed up for a further 4 years . The main endpoints were all-cause mortality during 4 years of follow-up from Q92 , and major fatal and non-fatal coronary-heart-disease events during 3 years of follow-up from Q92 . FINDINGS Among 4311 men with no history of coronary heart disease , stroke , or " other heart trouble " by Q92 and who did not report " poor health " , there were 219 deaths . In the inactive/occasionally active , light , moderate , and moderately vigorous/vigorous activity groups there were 101 ( 18.5/1000 person-years ) 48 ( 11.4 ) , 23 ( 7.3 ) , and 47 ( 9.1 ) deaths , respectively ( adjusted risk ratios 1.00 , 0.61 [ 95 % CI 0.48 - 0.86 ] , 0.50 [ 0.31 - 0.79 ] , 0.65 [ 0.45 - 0.94 ] ) . Men who were sedentary at Q1 and who began at least light activity by Q92 had significantly lower all-cause mortality than those who remained sedentary , even after adjustment for potential confounders ( risk ratio=0.55 [ 0.36 - 0.84 ] ) . Physical activity improved both cardiovascular mortality ( 0.66 [ 0.35 - 1.23 ] ) and non-cardiovascular mortality ( 0.48 [ 0.27 - 0.85 ] ) . The relation between  physical activity  at Q92 , changes in physical activity , and mortality were similar for men with pre-existing cardiovascular disease . INTERPRETATION Maintaining or taking up light or moderate physical activity reduces mortality and heart attacks in older men with and without diagnosed cardiovascular disease . Our results support public-health recommendations for older sedentary people to increase physical activity , and for active middle-aged people to continue their activity into old age This case-control study examines the association of vigorous and mild physical activity with  fall-related fractures in a community-dwelling population age 65 and older in South Florida .  Vigorous physical activity was defined as exercising , doing heavy housecleaning , or other hard labor three or more times per week in the month prior to the index date ; mild physical activity was defined as the number of hours per day subjects reported spending on their feet . A case was any subject who sustained a fall-related fracture ( ICD-9CM-800 through ICD-9CM-829 ) over a 21-month period ( n = 471 ) . Controls were at 10 % r and om sample selected from the Health Care Financing Administration Medicare files ( n = 712 ) . The presence of any limitation in activities of daily living ( ADL ) significantly modified the effect of vigorous physical activity . Physically active subjects with no limitations ( ADL = 0 ) were less likely to sustain a fall-related fracture than were inactive subjects with an adjusted odds ratio ( aOR ) of 0.6 , ( 0.5 - 0.8 95 % CI ) , and active subjects with any limitation ( ADL > or = 1 ) had an aOR of 3.2 ( 1.1 - 9.8 95 % CI ) . Limiting this analysis to 159 hip fracture cases produced similar results .  Mild physical activity  was not associated with fracture . These results suggest that vigorous physical activity is associated with a lower fracture risk among elderly persons who have no limitation in ADL and with a higher risk among those with any limitations & NA ; To investigate the relation between recreational physical activity and breast cancer , we conducted an analysis of a population ‐based case‐control study of women age 50‐64 years in western Washington State . The study included 537 patients with breast cancer diagnosed during 1988‐1990 and 492 r and omly selected population control women . Detailed information on recreational exercise habits and other risk factors for breast cancer was ascertained by structured in‐person interviews . A similar proportion of cases and controls reported exercise in the 2 years before the referent date ( about 50 % ) , or during ages 12‐21 years ( about 40 % ) . Compared with women who reported no exercise , there was a slightly decreased risk of breast cancer in women who exercised more than 1.5 hours per week in the 2 years before diagnosis ( cases ) or referent date ( controls ) [ odds ratio ( OR ) = 0.7 ; 95 % confidence interval ( CI ) = 0.4‐1.1 ] , or who engaged in at least some high‐intensity exercise ( OR = 0.7 ; 95 % CI = 0.4‐1.1 ) , but there was no clear decline in risk at the highest categories of duration or intensity . There was no association between  any intensity exercise at ages 12‐21 years and risk of breast cancer . These results indicate a weak negative association between physical activity and risk of breast cancer in middle‐aged women OBJECTIVES The purpose of this study was to determine whether walking is associated with a reduced risk of cardiovascular disease hospitalization and death in community-dwelling older men and women . DESIGN A prospect i ve study , with follow-up time of 4 to 5 years ( average 4.2 years ) . SETTING A western Washington health maintenance organization . PARTICIPANTS Men and women aged 65 years and older from a r and om sample of HMO enrollees invited by mail to participate in a health promotion intervention trial ( 36 % accepted the invitation and completed question naires ) . This report is based on 1645 older adults without severe disability and without history of heart disease . Vital status ascertainment was complete ( 100 % ) , and only 2.6 % did not complete the follow-up . MEASUREMENTS Reported frequency and duration of walking for exercise , work , err and s , pleasure , and hiking in the 2 weeks before baseline were used to classify hours of walking per week . The two main outcomes were : ( 1 ) cardiovascular disease hospitalizations with a discharge diagnosis of coronary ( ICD-9-CM 410 - 414 ) or other cardiovascular diseases ( ICD-9-CM 390 - 409 , 415 - 448 ) documented by computerized hospitalization records and ( 2 ) death . Numerous potential confounding factors were considered , including age , sex , treated high blood pressure , current estrogen use and chronic disease score ( ascertained by computerized medical and pharmacy records ) , and ethnicity , education , income , physical function , self-rated health status , smoking , alcohol intake , and body mass index ( ascertained by self-report on the mailed question naire ) . RESULTS Walking more than 4 hours/week was associated significantly with a reduced risk of cardiovascular disease hospitalization in both sexes combined compared with walking less than 1 hour/week ( age and sex-adjusted relative risk = 0.69 ; 95 % confidence interval , 0.52 - 0.90 ) . This association was not altered by adjustment for baseline cardiovascular risk factors and indicators of general health status . The association was present in all age groups , among those with and without physical limitations , and also among those who did and did not also participate in more vigorous physical activities . Walking more than 4 hours/week was also associated with a reduced risk of death ( age and sex-adjusted relative risk = 0.73 ; 95 % confidence interval , 0.48 - 1.10 ) , however , this association was substantially diminished by adjustment for cardiovascular risk factors and measures of general health status . CONCLUSIONS Walking more than 4 hours/week may reduce the risk of hospitalization for cardiovascular disease events . The association of walking more than 4 hours/week with reduced risk of death may be mediated by effects of walking on other risk factors . These findings provide much stronger evidence than previously available for advising older men and women to embark on or maintain a sustained program of walking to prevent cardiovascular disease events PURPOSE To examine the long-term association of leisure time physical activity ( LTPA ) and risk of death from coronary heart disease ( CHD ) and all-causes . METHODS Data are from a prospect i ve study of 12,138 middle-aged men at high risk for CHD participating in the MRFIT . Men were classified into deciles based on average min/d of LTPA reported at baseline , which were compared with cumulative CHD and all-cause mortality endpoints at the 16-year follow-up . RESULTS Men in the least-active decile of LTPA who averaged 4.9 min/d of LTPA ( range 0 to .9 min/d ) had excess age-adjusted mortality rates of 29 % and 22 % for CHD and all-causes , respectively , as compared to those in combined deciles 2 to 4 , who averaged 22.7 min/d of predominantly light and moderate LTPA ( range 10 - 36 min/d ) . No further decrement in mortality rates was noted in those in the higher declines of LTPA . These associations remained significant ( P < 0.05 ) after proportional hazards adjustments for additional possible confounding variables . CONCLUSION These data suggest that a relatively small amount ( 10 to 36 min/d ) of daily moderate intensity LTPA can significantly reduce premature mortality , particularly from CHD , in middle-aged and older men at high risk for CHD BACKGROUND Whether the major components of leisure physical activity ( number of types , intensity , frequency , and duration ) have independent contribution to mortality reduction and there is a minimum amount of activity beneficial for the elderly remain unclear . METHODS The prospect i ve follow-up study aim ed at examining the relationship between exercise components and total mortality in general elderly population . A total of 2113 persons aged 65 and older participating in 2001 Taiwan National Health Interview Survey were studied . Information regarding leisure physical activity , its energy parameters , other factors at baseline , and vital status at the end of 2003 was analyzed with Cox model . RESULTS A total of 197 deaths occurred during a 2-year follow-up . Regular exercisers reduced 35 % risk of death compared with sedentary individuals after adjustment for covariates . Moreover , exercisers with a weekly amount of energy exceeding 1000 kcal had significant benefit of risk reduction when energy expenditure is considered . There was a significant dose-response relationship between number of activity and the reduction in total mortality . The benefit on mortality reduction among the three components of total energy amount was only observed in intensity . CONCLUSIONS For the amount of energy dedicated to leisure physical activity , older persons are recommended to expend at least 1000 kcal per week through regular exercise for mortality reduction . In addition to energy amount , protection of exercise against death also increases with the number of activities . Among the three components of total amount of energy , only intensity is significantly associated with mortality reduction PURPOSE We examined the association between cardiorespiratory fitness and stroke mortality in men . METHODS This is a prospect i ve cohort study . We followed 16,878 men , ages 40 - 87 yr , who had a complete medical evaluation including a maximal treadmill exercise test and self-reported health habits .  There were 32 stroke deaths  during an average of 10 yr of follow-up ( 167,961 man-yr ) . RESULTS After adjustment for age and examination year , there was an inverse association between cardiorespiratory fitness and stroke mortality ( P = 0.005 for trend ) . This association remained after further adjustment for cigarette smoking , alcohol intake , body mass index , hypertension , diabetes mellitus , and parental history of coronary heart disease ( P = 0.02 for trend ) . High-fit men ( most fit 40 % ) had 68 % ( 95 % CI : 0.12 , 0.82 ) and moderate-fit men had 63 % ( 95 % CI : 0.17 , 0.83 ) lower risk of stroke mortality when compared with low-fit men ( least fit 20 % ) , respectively . CONCLUSIONS Moderate and high levels of cardiorespiratory fitness were associated with lower risk of stroke mortality in men in the Aerobics Center Longitudinal study population
target: Overall , the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified .
  Moreover , higher levels of physical activity reduce the risk for premature all-cause mortality .
  The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality
background: This systematic review examines critically the scientific basis for Canada 's Physical Activity Guide for Healthy Active Living for adults .
  Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases ( cardiovascular disease , stroke , hypertension , colon cancer , breast cancer , type 2 diabetes ( diabetes mellitus ) and osteoporosis ) .
  The strength of the relationship between physical activity and specific health outcomes is evaluated critically .