title: Exercise and working memory: an individual differences investigation. Exercise, Fitness, and Neurocognitive Function in Older Adults: The “Selective Improvement” and “Cardiovascular Fitness” Hypotheses Associations Between Sedentary Behaviors and Cognitive Function: Cross-Sectional and Prospective Findings From the UK Biobank Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning Effect of alternating postures on cognitive performance for healthy people performing sedentary work Effect of frequent interruptions of prolonged sitting on self-perceived levels of energy, mood, food cravings and cognitive function Too much sitting: the population health science of sedentary behavior. The Effects of Chronic Exercise on Attentional Networks The effect of experimentally induced sedentariness on mood and psychobiological responses to mental stress Active Workstations Do Not Impair Executive Function in Young and Middle-Age Adults Television watching and other sedentary behaviors in relation to risk of obesity and type 2 diabetes mellitus in women. Acute glucoregulatory and vascular outcomes of three strategies for interrupting prolonged sitting time in postmenopausal women: A pilot, laboratory-based, randomized, controlled, 4-condition, 4-period crossover trial Acute effects on cognitive performance following bouts of standing and light-intensity physical activity in a simulated workplace environment. Effect of Early Adult Patterns of Physical Activity and Television Viewing on Midlife Cognitive Function. Alternating bouts of sitting and standing attenuate postprandial glucose responses. Effects of a Sedentary Intervention on Cognitive Function A randomised control trial of the cognitive effects of working in a seated as opposed to a standing position in office workers Higher levels of objectively measured sedentary behavior is associated with worse cognitive ability: Two-year follow-up study in community-dwelling older adults
abstract: In the current work we asked whether executive function , as measured by tests of working memory capacity , might benefit from an acute bout of exercise and , more specifically , whether individuals who are lower or higher in working memory to begin with would be more or less affected by an exercise manipulation . Healthy adults completed working memory measures in a nonexercise ( baseline ) session and immediately following a 30-min self-paced bout of exercise on a treadmill ( exercise session ) . Sessions were conducted 1 week apart and session order was counterbalanced across participants . A significant Session x Working Memory interaction was obtained such that only those individuals lowest in working memory benefited from the exercise manipulation . This work suggests that acute bouts of exercise may be most beneficial for healthy adults whose cognitive performance is generally the lowest , and it demonstrates that the impact of exercise on cognition is not uniform across all individuals Background Although basic research has uncovered biological mechanisms by which exercise could maintain and enhance adult brain health , experimental human studies with older adults have produced equivocal results . Purpose This r and omized clinical trial aim ed to investigate the hypotheses that ( a ) the effects of exercise training on the performance of neurocognitive tasks in older adults is selective , influencing mainly tasks with a substantial executive control component and ( b ) performance in neurocognitive tasks is related to cardiorespiratory fitness . Methods Fifty-seven older adults ( 65–79 years ) participated in aerobic or strength- and -flexibility exercise training for 10 months . Neurocognitive tasks were selected to reflect a range from little ( e.g. , simple reaction time ) to substantial ( i.e. , Stroop Word – Color conflict ) executive control . Results Performance in tasks requiring little executive control was unaffected by participating in aerobic exercise .  Improvements in Stroop Word – Color task performance were found only for the aerobic exercise group . Changes in aerobic fitness were unrelated to changes in neurocognitive function . Conclusions Aerobic exercise in older adults can have a beneficial effect on the performance of speeded tasks that rely heavily on executive control . Improvements in aerobic fitness do not appear to be a prerequisite for this beneficial effect We investigated the cross-sectional and prospect i ve associations between different sedentary behaviors and cognitive function in a large sample of adults with data stored in the UK Biobank . Baseline data were available for 502,643 participants ( 2006 - 2010 , United Kingdom ) . Cognitive tests included  prospect  i  ve memory  ( baseline only : n = 171,585 ) , visual-spatial memory ( round 1 : n = 483,832 ; round 2 : n = 482,762 ) , fluid intelligence ( n = 165,492 ) , and short-term numeric memory ( n = 50,370 ) . After a mean period of 5.3 years , participants ( numbering from 12,091 to 114,373 , depending on the test ) also provided follow-up cognitive data . Sedentary behaviors ( television viewing , driving , and nonoccupational computer-use time ) were measured at baseline . At baseline , both television viewing and driving time were inversely associated with cognitive function across all outcomes ( e.g. , for each additional hour spent watching television , the total number of correct answers in the fluid intelligence test was 0.15 ( 99 % confidence interval : 0.14 , 0.16 ) lower . Computer-use time was positively associated with cognitive function across all outcomes . Both television viewing and driving time at baseline were positively associated with the odds of having cognitive decline at follow-up across most outcomes . Conversely , computer-use time at baseline was inversely associated with the odds of having cognitive decline at follow-up across most outcomes . This study supports health policies design ed to reduce television viewing and driving in adults Adults are sedentary for an alarming 9 to 10 hours per day ( 1 ) . Accordingly , the popular press has coined the phrase sitting is the new smoking to describe a current epidemic of developed nations ( 24 ) . Evidence indicates that sedentary time is associated with incident cardiovascular disease , incidence of cardiovascular diseaserelated risk factors , and mortality ( 5 , 6 ) . Of note , the risk conferred by prolonged sedentariness is eliminated only by high levels of moderate- to vigorous-intensity physical activity ( MVPA ) ( about 60 to 75 min/d ) , which exceed physical activity recommendations ( 7 , 8) . As such , sedentary behavior is now believed to represent a clinical ly important aspect of a person 's physical activity profile and is no longer considered simply the extreme low end of the physical activity continuum ( 5 ) . Studies linking sedentary behavior to health outcomes have relied almost exclusively on self-reported  sedentary time  , which is subject to reporting bias and measurement error ( 9 ) . A 2015 systematic review ( 5 ) identified only 1 study ( NHANES [ National Health and Nutrition Examination Survey ] ) that examined the association between objective ly measured sedentary time and health outcomes , a study limited by a small event rate ( 10 ) . New studies using NHANES data have since been published , with longer follow-up and higher event rates ( 1115 ) . However , some of these studies have reported an association between objective ly measured sedentary time and mortality ( 11 , 14 , 15 ) , but others have not ( 12 , 13 ) . Additional cohort studies are thus needed to rectify evidence gaps . Furthermore , studies using accelerometers to objective ly measure sedentary behavior conventionally operationalize sedentary time as the total number of sedentary minutes per day . This approach ignores patterns of accumulated sedentary behavior over time . For example , accumulation of sedentary time in a few long bouts or many short bouts represents 2 distinct patterns of sedentary time accrual . Experimental studies have shown that acute periods of prolonged , uninterrupted sedentary behavior cause greater detrimental cardiometabolic effects than sedentary behavior that is periodically interrupted ( 1618 ) , suggestive that it is not just total sedentary time that is relevant to health outcomes , but also the manner in which it is accumulated . Few longitudinal studies , however , have explored the association between prolonged , uninterrupted sedentary behavior and mortality to corroborate these findings . To inform guidelines on reducing sedentary behavior ( target reductions in overall sedentary time or target interruption of prolonged sedentary bouts ) , evidence from prospect i ve studies is needed to 1 ) confirm the association between total sedentary time and mortality using objective measures , 2 ) determine whether prolonged sedentary bouts confer risk for death , and 3 ) eluci date whether the total volume of sedentary time and its pattern of accumulation individually or jointly contribute to risk for death . The purpose of this study , therefore , was to examine the association between objective ly measured sedentary time ( both total volume and accrual in prolonged bouts ) and all-cause mortality in a national cohort of U.S. middle-aged and older adults enrolled in the REGARDS ( Reasons for Geographic and Racial Differences in Stroke ) study . Methods Study Population REGARDS is a population -based study design ed to examine racial and regional disparities in stroke . It comprises 30239 white and black adults aged 45 years or older enrolled between 2003 and 2007 from across the contiguous United States ( 19 , 20 ) . Detailed design and methods for REGARDS are described elsewhere ( 21 ) . Briefly , demographic and cardiovascular risk factor data were collected by telephone interview and an in-home physical assessment on enrollment . A detailed summary of baseline measures is provided in the Supplement . Participants ( or their proxies ) were then followed for 6-month intervals to ascertain vital status . Objective measurements of sedentary behavior were collected from active REGARDS participants from 2009 to 2013 ( mean time from study enrollment , 5.7 years [ SD , 1.5 ] ; range , 1.9 to 9.5 years ) ( 22 ) . A total of 7985 participants adhered to accelerometer wear requirements ( 4 days with accelerometer wear 10 hours ) , provided follow-up data , and were available for the current analyses ( Supplement Figure 1 ) . Supplement Table 1 shows the characteristics of included versus excluded REGARDS participants . The REGARDS study protocol was approved by the institutional review boards of participating institutions . All participants provided informed consent . Supplement . Supplementary Material Accelerometer Data Collection Methods for accelerometer data collection are described elsewhere ( 22 ) . Briefly , participants were fitted with an Actical ( Philips Respironics ) accelerometer secured to their right hip using a nylon belt and were instructed to wear the device during waking hours for 7 consecutive days . The Actical had been vali date d formeasurement of physical activity and sedentary behavior and was shown to have acceptable reliability ( 2325 ) . Activity counts were summed over 1-minute epochs . Nonwear periods were defined as at least 150 consecutive minutes of 0 activity counts . This nonwear algorithm was previously vali date d against daily log sheets in REGARDS participants ( 26 ) . Measurements of 0 to 49 , 50 to 1064 , and at least 1065 counts per minute were defined as sedentary behavior , light-intensity physical activity , and MVPA , respectively , as determined in a laboratory-based calibration study ( 27 ) . A sedentary bout was defined as consecutive minutes in which the accelerometer registered fewer than 50 counts per minute . A sedentary break was defined as at least 1 minute in which 50 or more counts per minute were registered after a sedentary bout . Both sedentary bouts and breaks were exclusively continuous periods , with no interruptions or nonwear intervals allowed in the definition . Outcome Ascertainment All-cause mortality was the primary outcome , defined as any death after completion of the accelerometer protocol regardless of cause . Date s of death were confirmed through review of death certificates , medical records , and administrative data bases . Deaths through 4 September 2015 were included in the current analysis . Statistical Analysis Sedentary and physical activity variables were averaged across compliant days ( 10 hours of wear ) . Because of a high correlation between total sedentary time and wear time ( Supplement Figure 2 ) , we corrected for the influence of wear time by st and ardizing total sedentary time to 16 hours of wear time per day using the residuals obtained when regressing total sedentary time on wear time ( see Methods section of the Supplement ) ( 2830 ) . Participants were stratified into quartiles according to total sedentary time and , separately , mean sedentary bout duration ( a measure of overall prolonged , uninterrupted sedentary behavior ) . Cox proportional hazards regression modeling was used to calculate the hazard ratio ( HR ) for all-cause mortality associated with quartiles of total sedentary time ( and separately , mean sedentary bout length ) . Crude HRs were initially calculated . Subsequent HRs were calculated after adjustment for age , race , sex , region of residence , education , and season the accelerometer was worn ( model 1 ) , with further adjustment for current smoking , alcohol use , body mass index ( BMI ) , diabetes , hypertension , dyslipidemia , estimated glomerular filtration rate less than 60 mL/min/1.73 m2 , atrial fibrillation , history of coronary heart disease , and history of stroke ( model 2 ) . Models were additionally adjusted for MVPA expressed continuously ( model 3 ) . Tests for linear trend across quartiles were conducted by including the quartile for each participant as an ordinal variable in regression models . Proportional hazards assumptions were confirmed with a Kolmogorov-type supremum test ( 31 ) . The above analyses were then repeated in a fully adjusted model , testing interactions for age ( < 65 and 65 years ) , sex ( male and female ) , race ( black and white ) , BMI category ( normal weight and overweight or obese ) , and MVPA category ( < 150 min/wk and 150 min/wk ) . As a secondary analysis , we examined the continuous doseresponse relationship between each sedentary characteristic and all-cause mortality in a fully adjusted model ( model 3 ) using restricted cubic splines ( 32 ) . Cubic polynomials were fitted with the mean of each sedentary characteristic set as the reference and knots placed at the 5th , 35th , 65th , and 95th percentiles ( 33 ) . Nonlinear associations were evaluated using the likelihood ratio test . For nonlinear associations , spline models were used to describe the associations and when the association was determined to be linear , a linear model was used . Because of multicollinearity between total sedentary time and mean sedentary bout duration ( r= 0.61 ) , both variables were not included in the same model . Alternatively , to examine the individual and joint associations of total sedentary time and prolonged , uninterrupted sedentary behavior with mortality , participants were classified into 4 categories : low total sedentary time ( < 750 min/d ) and low prolonged sedentary bout time ( < 10 min/bout ) , low total sedentary time  and high prolonged sedentary bout time  ( 10 min/bout ) , high total sedentary time  ( 750 min/d ) and low prolonged sedentary bout time , and high total sedentary time and high prolonged sedentary bout time . Hazard ratios for all-cause mortality were calculated for each joint category in comparison with the lowlow group in a fully adjusted model ( model 3 ) . Thresholds for total sedentary time ( 750 min/d ) and mean sedentary bout duration ( 10 min/bout ) were selected on the basis of the restricted cubic splines and were confirmed using a method described by Contal and O'Quigley ( see Methods section of the Supplement ) ( 34 ) . To allow for the possibility that sedentary bouts Abstract Recent attention has highlighted the importance of reducing sedentary time for maintaining health and quality of life . However , it is unclear how changing sedentary behavior may influence executive functions and self-regulatory strategy use , which are vital for the long-term maintenance of a health behavior regimen . The purpose of this cross-sectional study is to examine the estimated self-regulatory and executive functioning effects of substituting 30 min of sedentary behavior with 30 min of light activity , moderate-to-vigorous physical activity ( MVPA ) , or sleep in a sample of older adults . This study reports baseline data collected from low-active healthy older adults ( N = 247 , mean age 65.4 ± 4.6 years ) recruited to participate in a 6 month r and omized controlled exercise trial examining the effects of various modes of exercise on brain health and function . Each participant completed assessment s of  physical activity self-regulatory strategy use ( i.e. ,  self-monitoring , goal - setting , social support , reinforcement , time management , and relapse prevention )  and executive functioning . Physical activity and sedentary behaviors  were measured using accelerometers during waking hours for seven consecutive days at each time point . Isotemporal substitution analyses were conducted to examine the effect on self-regulation and executive functioning should an individual substitute sedentary time with light activity , MVPA , or sleep . The substitution of sedentary time with both sleep and MVPA influenced both self-regulatory strategy use and executive functioning . Sleep was associated with greater self-monitoring ( B = .23 , p = .02 ) , goal - setting ( B = .32 , p < .01 ) , and social support ( B = .18 , p = .01 ) behaviors . Substitution of sedentary time with MVPA was associated with higher accuracy on 2-item ( B = .03 , p = .01 ) and 3-item ( B = .02 , p = .04 ) spatial working memory tasks , and with faster reaction times on single ( B = −23.12 , p = .03 ) and mixed-repeated task-switching blocks ( B = −27.06 , p = .04 ) . Substitution of  sedentary  time with sleep was associated with marginally faster reaction time on mixed-repeated task-switching blocks ( B = −12.20 , p = .07 ) and faster reaction time on mixed-switch blocks ( B = 17.21 , p = .05 ) , as well as reduced global reaction time switch cost ( B = −16.86 , p = .01 ) . Substitution for light intensity physical activity did not produce significant effects . By replacing sedentary time with sleep and MVPA , individuals may bolster several important domains of self-regulatory behavior and executive functioning . This has important implication s for the design of long-lasting health behavior interventions . Trial Registration clinical trials.gov identifier NCT00438347 Abstract Prolonged sitting is a risk factor for several diseases and the prevalence of worksite-based interventions such as sit-to-st and workstations is increasing . Although their impact on sedentary behaviour has been regularly investigated , the effect of working in alternating body postures on cognitive performance is unclear . To address this uncertainty , 45 students participated in a two-arm , r and omised controlled cross-over trial under laboratory conditions . Subjects executed vali date d cognitive tests ( working speed , reaction time , concentration performance ) either in sitting or alternating working postures on two separate days ( Clinical Trials.gov Identifier : NCT02863731 ) . MANOVA results showed no significant difference in cognitive performance between trials executed in alternating , st and ing or sitting postures . Perceived workload did not differ between sitting and alternating days . Repeated measures ANOVA revealed significant learning effects regarding concentration performance and working speed for both days . These results suggest that working posture did not affect cognitive performance in the short term . Practitioner Summary : Prior reports indicated health-related benefits based on alternated ( sit/st and ) body postures . Nevertheless , their effect on cognitive performance is unknown . This r and omised controlled trial showed that working in alternating body postures did not influence reaction time , concentration performance , working speed or workload perception in the short term Background While physical activity has been shown to improve cognitive performance and well-being , office workers are essentially sedentary . We compared the effects of physical activity performed as ( i ) one bout in the morning or ( ii ) as microbouts spread out across the day to ( iii ) a day spent sitting , on mood and energy levels and cognitive function . Methods In a r and omized crossover trial , 30 sedentary adults completed each of three conditions : 6 h of uninterrupted sitting ( SIT ) , SIT plus 30 min of moderate-intensity treadmill walking in the morning ( ONE ) , and SIT plus six hourly 5-min microbouts of moderate-intensity treadmill walking ( MICRO ) .  Self-perceived energy , mood , and appetite were assessed with visual analog scales . Vigor and fatigue were assessed with the Profile of Mood State question naire . Cognitive function was measured using a flanker task and the Comprehensive Trail Making Test . Intervention effects were tested using linear mixed models . Results Both ONE and MICRO increased self-perceived energy and vigor compared to SIT ( p < 0.05 for all ) . MICRO , but not ONE , improved mood , decreased levels of fatigue and reduced food cravings at the end of the day compared to SIT ( p < 0.05 for all ) . Cognitive function was not significantly affected by condition . Conclusions In addition to the beneficial impact of physical activity on levels of energy and vigor , spreading out physical activity throughout the day improved mood , decreased feelings of fatigue and affected appetite . Introducing short bouts of activity during the workday of sedentary office workers is a promising approach to improve overall well-being at work without negatively impacting cognitive performance . Trial registration NCT02717377 , registered 22 March 2016 Even when adults meet physical activity guidelines , sitting for prolonged periods can compromise metabolic health .  Television ( TV ) time and objective measurement studies show deleterious associations , and breaking up sedentary time is beneficial .  Sitting time , TV time , and time sitting in automobiles increase premature mortality risk . Further evidence from prospect i ve studies , intervention trials , and population -based behavioral studies is required The aim of this study was to test the hypothesis that chronic physical exercise improves attentional control in young healthy participants . To do this , we compared the performance of physically active and passive participants in the Attentional Network Task , which allows for the assessment of the executive , orienting and alerting networks . The results showed a selective positive effect of exercise on the executive network . These results extend the evidence gathered in children , older adults and certain clinical population s suggesting that exercise can also improve attentional control in healthy young adults Background Evidence suggests a link between sedentary behaviours and depressive symptoms . Mechanisms underlying this relationship are not understood , but inflammatory processes may be involved . Autonomic and inflammatory responses to stress may be heightened in sedentary individuals contributing to risk , but no study has experimentally investigated this . Aims To examine the effect of sedentary time on mood and stress responses using an experimental design . Method Forty-three individuals were assigned to a free-living sedentary condition  and to  a control condition ( usual activity ) in a cross-over , r and omised fashion and were tested in a psychophysiology laboratory after spending 2 weeks in each condition . Participants completed mood question naires ( General Health Question naire and Profile of Mood States ) and wore a motion sensor for 4 weeks . Results Sedentary time increased by an average of 32 min/day ( P = 0.01 ) during the experimental condition compared with control . Being sedentary result ed in increases in negative mood independent of changes in moderate to vigorous physical activity ( ΔGHQ = 6.23 , ΔPOMS = 2.80 ) . Mood disturbances were associated with greater stress-induced inflammatory interleukin-6 ( IL-6 ) responses ( β = 0.37 ) . Conclusions Two weeks of exposure to greater free-living sedentary time result ed in mood disturbances independent of reduction in physical activity . Stress-induced IL-6 responses were associated with changes in mood Purpose This study aim ed to examine the effects of self-selected low-intensity walking on an active workstation on executive functions ( EF ) in young and middle-age adults . Methods Using a within-subjects design , 32 young ( 20.6 ± 2.0 yr ) and 26 middle-age ( 45.6 ± 11.8 yr ) adults performed low-intensity treadmill walking and seated control conditions in r and omized order on separate days , while completing an EF test battery . EF was assessed using modified versions of the Stroop ( inhibition ) , Sternberg ( working memory ) , Wisconsin Card Sorting ( cognitive flexibility ) , and Tower of London ( global EF ) cognitive tasks  . Behavioral performance outcomes were assessed using composite task z-scores and traditional measures of reaction time and accuracy . Average HR and step count were also measured throughout . Results The expected task difficulty effects were found for reaction time and accuracy . No significant main effects or interactions as a function of treadmill walking were found for tasks assessing global EF and the three individual EF domains . Accuracy on the Tower of London task was slightly impaired during slow treadmill walking for both age-groups . Middle-age adults displayed longer planning times for more difficult conditions of the Tower of London during walking compared with sitting . A 50-min session of low-intensity treadmill walking on an active workstation result ed in accruing approximately 4500 steps . Conclusions These findings suggest that executive function performance remains relatively unaffected while walking on an active workstation , further supporting the use of treadmill workstations as an effective approach to increase physical activity and reduce sedentary time in the workplace 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 Background Prolonged sitting is associated with cardiometabolic and vascular disease . Despite emerging evidence regarding the acute health benefits of interrupting prolonged sitting time , the effectiveness of different modalities in older adults ( who sit the most ) is unclear . Methods In preparation for a future r and omized controlled trial , we enrolled 10 sedentary , overweight or obese , postmenopausal women ( mean age 66 years ±9 ; mean body mass index 30.6 kg/m2 ±4.2 ) in a 4-condition , 4-period crossover feasibility pilot study in San Diego to test 3 different sitting interruption modalities design ed to improve glucoregulatory and vascular outcomes compared to a prolonged sitting control condition . The interruption modalities included : a ) 2 minutes st and ing every 20 minutes ; b ) 2 minutes walking every hour ; and c ) 10 minutes st and ing every hour . During each 5-hr condition , participants consumed two identical , st and ardized meals . Blood sample s , blood pressure , and heart rate were collected every 30 minutes . Endothelial function of the superficial femoral artery was measured at baseline and end of each 5-hr condition using flow-mediated dilation ( FMD ) . Participants completed each condition on separate days , in r and omized order . This feasibility pilot study was not powered to detect statistically significant differences in the various outcomes , however , analytic methods ( mixed models ) were used to test statistical significance within the small sample size . Results Nine participants completed all 4 study visits , one participant completed 3 study visits and then was lost to follow up . Net incremental area under the curve ( iAUC ) values for postpr and ial plasma glucose and insulin during the 5-hr sitting interruption conditions were not significantly different compared to the control condition . Exploratory analyses revealed that the 2-minute st and ing every 20 minutes and the 2-minute walking every hour conditions were associated with a significantly lower glycemic response to the second meal compared to the first meal ( i.e. , condition-matched 2-hour post-lunch glucose iAUC was lower than 2-hour post-breakfast glucose iAUC ) that withstood Bonferroni correction ( p = 0.0024 and p = 0.0084 , respectively ) . Using allometrically scaled data , the 10-minute st and ing every hour condition result ed in an improved FMD response , which was significantly greater than the control condition after Bonferroni correction ( p = 0.0033 ) . Conclusion This study suggests that brief interruptions in prolonged sitting time have modality-specific glucoregulatory and vascular benefits and are feasible in an older adult population . Larger laboratory and real-world intervention studies of pragmatic and effective methods to change sitting habits are needed . Trial registration Clinical Trials.gov NCT02743286 OBJECTIVES To compare acute cognitive effects following bouts of st and ing ( ST AND ) , cycling ( CYCLE ) and walking ( WALK ) to a sit-only ( SIT ) condition . DESIGN R and omized cross-over full-factorial study . METHODS Nine overweight ( BMI = 29±3kg/m2 ) adults ( 30±15years ; 7 females , 2 males ) completed four conditions ( SIT , ST AND , WALK and CYCLE ) across a 6h period with a 7days washout period between conditions . SIT consisted of uninterrupted sitting . Experimental conditions included intermittent bouts of st and ing ( ST AND ) , cycling ( CYCLE ) and walking ( WALK ) . A cognitive performance battery ( Cogstate ) was completed twice in a seated position following bouts of st and ing and light-intensity physical activity . Mixed-effects models compared between-condition differences in st and ardized score ( z-score ) , accuracy ( % ) , and speed ( log10ms ) . RESULTS Cognitive performance z-score and accuracy measures were higher during ST AND , CYCLE and WALK ( P<0.05 ) conditions compared to the SIT condition . CYCLE was better than other experimental conditions . CONCLUSIONS Compared to uninterrupted sitting , short bouts of st and ing or light-intensity cycling and walking  may improve acute cognitive performance IMPORTANCE Sedentary behaviors and physical inactivity are not only increasing worldwide but also are critical risk factors for adverse health outcomes . Yet , few studies have examined the effects of sedentary behavior on cognition or the long-term role of either behavior in early to middle adulthood . OBJECTIVE To investigate the association between 25-year patterns of television viewing and physical activity and midlife cognition . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve study of 3247 adults ( black and white races ; aged 18 - 30 years ) enrolled in the Coronary Artery Risk Development in Young Adults ( CARDIA ) Study ( March 25 , 1985 , to August 31 , 2011 ) . Data analysis was performed June 1 , 2014 , through April 15 , 2015 . MAIN OUTCOMES AND MEASURES We assessed television viewing and physical activity at repeated visits ( ≥3 assessment s ) over 25 years using a vali date d question naire . A 25-year pattern of high television viewing was defined as watching TV above the upper baseline quartile ( > 3 hours/d ) for more than two-thirds of the visits , and a 25-year pattern of low physical activity was defined as activity levels below the lower , sex-specific baseline quartile for more than two-thirds of the of the visits . We evaluated cognitive function at year 25 using the Digit Symbol Substitution Test ( DSST ) , Stroop test , and Rey Auditory Verbal Learning Test . RESULTS At baseline , the mean ( SD ) age of the 3247 study participants was 25.1 ( 3.6 ) years , 1836 ( 56.5 % ) were female , 1771 ( 54.5 % ) were white , and 3015 ( 92.9 % ) had completed at least high school . Compared with participants with low television viewing , those with high television viewing during 25 years ( 353 of 3247 [ 10.9 % ] ) were more likely to have poor cognitive performance ( < 1 SD below the race-specific mean ) on the DSST and Stroop test , with findings reported as adjusted odds ratio ( 95 % CI ) : DSST , 1.64 ( 1.21 - 2.23 ) and Stroop test , 1.56 ( 1.13 - 2.14 ) , but not the Rey Auditory Verbal Learning Test , adjusted for age , race , sex , educational level , smoking , alcohol use , body mass index , and hypertension . Low physical activity during 25 years in 528 of 3247 participants ( 16.3 % ) was significantly associated with poor performance on the DSST , 1.47 ( 1.14 - 1.90 ) . Compared with participants with low television viewing and high physical activity , the odds of poor performance were almost 2 times higher for adults with both high television viewing and low physical activity in 107 of 3247 ( 3.3 % ) ( DSST , 1.95 [ 1.19 - 3.22 ] , and Stroop test , 2.20 [ 1.36 - 3.56 ] ) . CONCLUSIONS AND RELEVANCE High television viewing and low physical activity in early adulthood were associated with worse midlife executive function and processing speed . This is one of the first studies to demonstrate that these risk behaviors may be critical targets for prevention of cognitive aging even before middle age PURPOSE This study aim ed to examine whether reductions in sitting time through alternating 30-min bouts of sitting and st and ing can reduce postpr and ial glucose , insulin , and triglyceride responses . METHODS Twenty-three overweight/obese sedentary office workers ( 17 males and six females ; mean ± SD : age , 48.2 ± 7.9 yr ; body mass index , 29.6 ± 4.0 kg · m(-2 ) ) undertook two short-term ( 5 d ) experimental conditions in an equal , r and omized ( 1:1 ) order . In a simulated office environment , participants performed typical occupational tasks for 8 h · d(-1 ) while in a 1 ) seated work posture ( control condition ) or 2 ) interchanging between a seated and st and ing work posture every 30 min using an electric , height-adjustable workstation ( intervention condition ) . Fasting and postpr and ial blood sample s after a mixed test drink were collected hourly for 4 h on days 1 and 5 of each condition to assess serum insulin , plasma glucose , and triglycerides . Dietary intake  ( kJ · d(-1 ) ) and physical activity  were st and ardized during each condition . The trial was registered with the Australian New Zeal and Clinical Trials Registry ( ACTRN12611000632998 ) . RESULTS After adjustment for time ( days 1 and 5 ) , incremental area under the analyte time curve differed significantly between conditions for plasma glucose ( P = 0.007 ) but not for serum insulin or plasma triglycerides . Adjusted mean glucose incremental area under the analyte time curve was lowered by 11.1 % after the intervention condition ( 6.38 mM · h(-1 ) ( confidence interval , 5.04 - 7.71 ) ) relative to the control condition ( 7.18 mM · h(-1 ) ( confidence interval , 5.85 - 8.52 ) ) . No temporal changes ( days 1 vs 5 ) between conditions were observed . CONCLUSIONS Alternating st and ing and sitting in 30-min bouts results in modest beneficial effects on postpr and ial glucose responses in overweight/obese office workers Purpose : To examine the effects of a free-living , sedentary-inducing intervention on cognitive function . Design : R and omized controlled , parallel group intervention . Setting : University campus . Participants : Thirty-three young adults ( n = 23 intervention ; n = 10 control ) . Measures : The intervention group was asked to eliminate all exercise and minimize steps to ≤5000 steps/day for 1 week , whereas the control group was asked to continue normal physical activity ( PA ) levels for 1 week . Both groups completed a series of  8 cognitive function assessment s ( assessing multiple parameters of cognition )  preintervention and immediately postintervention . The intervention group was asked to resume normal PA levels for 1 week postintervention and completed the cognitive assessment s for a third time at 2 weeks postintervention . Analysis : Split-plot repeated- measures analysis of variance . Results : The results of our statistical analyses showed that the group × time interaction effect was not significant ( P > .05 ) for any of the evaluated cognitive parameters . Conclusion : These findings demonstrate the need for future experimental investigations of sedentary behavior to better underst and its effects on cognitive function . However , although previous work has demonstrated favorable effects of acute and chronic PA on cognitive function , our findings suggest that a 1-week period of reduced PA does not detrimentally affect cognitive function , which may have encouraging implication s for individuals going through a temporary relapse in PA Abstract Sedentary behaviour is increasing and has been identified as a potential significant health risk , particularly for desk-based employees . The development of sit-st and workstations in the workplace is one approach to reduce sedentary behaviour . However , there is uncertainty about the effects of sit-st and workstations on cognitive functioning .  A sample of 36 university staff participated in a within-subjects r and omised control trial examining the effect of sitting vs. st and ing for one hour per day for five consecutive days on attention , information processing speed , short-term memory , working memory and task efficiency . The results of the study showed no statistically significant difference in cognitive performance or work efficiency between the sitting and st and ing conditions , with all effect sizes being small to very small ( all ds < .2 ) . This result suggests that the use of sit-st and workstations is not associated with a reduction in cognitive performance . Practitioner Summary : Although it has been reported that the use of sit-st and desks may help offset adverse health effects of prolonged sitting , there is scant evidence about changes in productivity . This r and omised control study showed that there was no difference between sitting and st and ing for one hour on cognitive function or task efficiency in university staff Background : A number of cross‐sectional studies have suggested that higher levels of  sedentary behavior ( SB ) are associated with worse cognitive abilities  in older age . There is a paucity of longitudinal studies investigating this relationship utilizing objective ly assessed SB . This study investigated the relationship between objective ly assessed SB and future cognitive abilities in a cohort of older adults . Methods : A longitudinal study over 22.12 ± 1.46 months including 285 community‐dwelling older adults across 14 regions in Taiwan was undertaken . Cognitive ability was ascertained using a Chinese version of the Ascertain Dementia 8‐item Question naire ( AD8 ) and SB captured by 7 days accelerometer data . Multivariable negative binomial regression models adjusted for confounders were undertaken . Results : 274 community‐dwelling older adults finished the study ( age = 74.6 ± 6.2 , % female = 54.4 % ) . At baseline , 20.1 % ( n = 55 ) , 48.5 % ( n = 133 ) and 31.4 % ( n = 86 ) of the sample engaged in high ( 11 + h ) , medium ( 7–10.99 h ) and low ( < 7 h ) of SB respectively . In the fully adjusted model , higher levels of SB were associated with an increased risk of worse cognitive ability at follow up ( adjusted rate ratio (ARR)1.09 ( 95%CI:1.00–1.19 ) ) , with the strongest relationship evident in those engaging in over 11 h of SB ( ARR 2.27 ( 95%CI:1.24–4.16 ) ) . The relationship remained evident after adjusting for depressive symptoms and physical activity . Conclusion : Our data suggests that objective ly assessed SB , particularly when over 11 h a day , is independently associated with worse cognitive ability over a two year period . Our data adds to the pressing reasons to reduced SB in older age . HighlightsFirst prospect i ve study to investigate objective  ly sedentary behavior ( SB ) and cognition in older adults . Higher levels of objective SB were independently associated with worse cognitive ability over two years . This relationship was most pronounced in older people spending over 11 h a day being sedentary
target: Conclusion : These data suggest that sedentary behavior is not associated with changes in cognitive performance in interventions that intend to reduce sedentary behavior .
background: Background : It is now well-established that sedentarity has a negative impact on the physiological functioning and health of humans , whereas very little is known about the psychological repercussions , especially in cognitive functioning .
  Yet , study ing the cognitive effects of the sedentary lifestyle is particularly relevant in the short term for productivity and in the long term for cognitive health ( accelerated aging ) .
  This systematic review therefore aims to make an inventory of the potential cognitive effects of sedentarity at the workplace .
  Methods : Pubmed , PsycINFO , Cochrane , Web of Science , and Scopus were search ed for English- language peer- review ed articles published between January 1 , 2000 and December 31 , 2017 to identify studies including sedentary behavior  and objective measures from cognitive domains ( cognitive inhibition , cognitive flexibility , working memory , etc . ) .