title: Childhood cardiorespiratory fitness, muscular fitness and adult measures of glucose homeostasis. Tracking of muscular strength and power from youth to young adulthood: Longitudinal findings from the Childhood Determinants of Adult Health Study. Adolescent determinants of cardiovascular risk factors in adult men and women Muscle strength in youth and cardiovascular risk in young adulthood (the European Youth Heart Study) Muscle strength in adolescent men and future musculoskeletal pain: a cohort study with 17 years of follow-up Enhanced bone mass and physical fitness in young female handball players. Bone mass and lifetime physical activity in Flemish males: a 27-year follow-up study. The Significance of High Lumbar Mobility and Low Lumbar Strength for Current and Future Low Back Pain In Adolescents Relationship of physical fitness to prevalence and incidence of overweight among schoolchildren. Strength training increases insulin-mediated glucose uptake, GLUT4 content, and insulin signaling in skeletal muscle in patients with type 2 diabetes. Relationships between physical activity and physical capacity in adolescent females and bone mass in adulthood. Low Back Pain in the Young A Prospective Three‐Year Follow‐up Study of Subjects With and Without Low Back Pain Weight-bearing, muscle loading and bone mineral accrual in pubertal girls--a 2-year longitudinal study. A 9-Month Jumping Intervention to Improve Bone Geometry in Adolescent Male Athletes Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies
abstract: OBJECTIVES To assess whether childhood cardiorespiratory fitness ( CRF ) and muscular fitness phenotypes ( strength , power , endurance ) predict adult glucose homeostasis measures . DESIGN Prospect i ve longitudinal study . METHODS Study examining participants who had physical fitness measured in childhood ( aged 7 - 15 years ) and who attended follow-up clinics approximately 20 years later  and provided  a fasting blood sample which was tested for glucose and insulin . Physical fitness measurements included muscular strength ( right and left grip , shoulder flexion , shoulder and leg extension ) , power ( st and ing long jump distance ) and endurance ( number of push-ups in 30s ) , and CRF ( 1.6 km run duration ) . In adulthood , fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance ( HOMA2-IR ) and beta cell function ( HOMA2-β ) . RESULTS A st and ard deviation increase in childhood CRF or muscular strength ( males ) was associated with fasting glucose ( CRF : β=-0.06mmol/L ) , fasting insulin ( CRF : β=-0.73mU/L ; strength : β=-0.40mU/L ) , HOMA2-IR ( CRF : β=-0.06 ; strength : β=-0.05 ) and HOMA2-β ( CRF : β=-3.06 % ; strength : β=-2.62 % ) in adulthood , independent of the alternative fitness phenotype ( all p<0.01 ) . Adjustment for childhood waist circumference reduced the effect by 17 - 35 % for CRF and 0 - 15 % for muscular strength ( males ) and statistical significance remained for all associations expect between CRF , fasting glucose and HOMA2-β ( p>0.06 ) . CONCLUSIONS CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin , insulin resistance and beta cell function in adulthood . Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis OBJECTIVES Low muscular fitness levels have previously been reported as an independent risk factor for chronic disease outcomes . Muscular fitness tracking , the ability to maintain levels measured at one point in time to another point in time , was assessed from youth to adulthood to provide insight into whether early identification of low muscular fitness in youth is possible . DESIGN Prospect i ve longitudinal study . METHODS Study including 623 participants who had muscular fitness measures in 1985 ( aged 9 , 12 or 15 years ) and again 20 years later in young adulthood . Measures of muscular fitness were strength ( right and left grip , leg , shoulder extension and flexion measured by dynamometer , and a combined strength score ) and power ( st and ing long jump distance ) . RESULTS Strength and power were relatively stable between youth and adulthood ; the strongest tracking correlations were observed for the combined strength score ( r=0.47 , p≤0.001 ) , right grip strength ( r=0.43 , p≤0.001 ) and st and ing long jump ( r=0.43 , p≤0.001 ) . Youth in the lowest third of muscular fitness had an increased risk of remaining in the lowest third of muscular fitness in adulthood ( strength : relative risk (RR)=4.70 , 95 % confidence interval ( CI ) ( 3.19 , 6.92 ) ; power : RR=4.06 ( 2.79 , 5.90 ) ) . CONCLUSIONS Youth with low muscular fitness are at increased risk of maintaining a low muscular fitness level into adulthood . These findings warrant investigation into the long term effects of early interventions that focus on improving low muscular fitness levels in youth which could potentially improve adult muscular fitness and reduce future chronic disease outcomes Aims : To investigate how physical activity , physical performance and sociodemographic characteristics at the age of 16 are related to adult health habits ( physical activity , dietary intake , smoking ) and biological risk factors for cardiovascular diseases ( being overweight , low aerobic fitness , unfavorable levels of serum lipids , high blood pressure ) . Methods : A r and omly selected group of 220 male and 205 female students at 16 years of age was tested in 1974 , and reinvestigated 18 years later . Results : The predictive health profiles for adult lifestyle and biological risk factors were different in men and women . Leisure sports activity along with high performance in the nine-minute run among the boys and in the two-h and lift test among the girls were significant predictors of adult physical activity . A positive attitude to aerobic exercise  and high performance in the nine-minute run test among the boys and high marks in physical education among the girls decreased the risk of smoking .  Leisure sports activities together with body mass index at young ages were the most powerful predictors of adult biological risk factors , but attitudes to sports and educational level were also significant determinants . Conclusion : These results contribute to the knowledge of which factors at young ages may promote adult healthy habits in particular physical activities Background Whether muscle strength in youth is related to cardiovascular risk later in life independent of cardiorespiratory fitness is unclear . Methods We examined the independent association of isometric muscle strength in youth with cardiovascular risk factors in young adulthood using data from the Danish European Youth Heart Study ; a population -based prospect i ve cohort study among boys and girls ( n=332 ) followed for up to 12 years . In youth maximal voluntary contractions during isometric back extension and abdominal flexion were determined using a strain-gauge dynamometer and cardiorespiratory fitness was obtained from a maximal cycle ergometer test . Cardiovascular risk factors were obtained in youth and in young adulthood . Associations were examined using multivariable-adjusted regression models including major confounding factors . Results Each 1 SD difference in isometric muscle strength in youth ( 0.17 N/kg ) was inversely associated with body mass index ( BMI ; −0.60 kg/m2 , 95 % CI −0.97 to −0.22 ) , triglyceride ( −0.09 mmol/l , 95 % CI −0.16 to −0.02 ) , diastolic blood pressure ( BP ) ( −1.22 mm Hg , 95 % CI −2.15 to −0.29 ) and a composite cardiovascular risk factor score ( −0.61 SD , 95 % CI −1.03 to −0.20 ) in young adulthood in multivariable-adjusted analyses including fitness . Associations to triglyceride , diastolic BP and the cardiovascular risk factor score remained with additional adjustment for waist circumference or BMI . Each 1 SD difference in isometric muscle strength in youth was significantly associated with 0.59 ( 95 % CI 0.40 to 0.87 ) lower odds of general overweight/obesity in young adulthood ( p=0.007 ) and was marginally associated with incident raised BP , raised triglyceride and low high-density lipoprotein cholesterol . Conclusions This study suggests that greater isometric muscle strength in youth is associated with lower levels of cardiovascular risk factors in young adulthood independent of fitness , adiposity and other confounding factors Objectives Musculoskeletal pain is highly prevalent throughout adulthood with a major impact on health , function and participation in the society . Still , the association between muscle strength and development of musculoskeletal pain is unclear . We aim ed to study whether overall muscle strength in adolescent men is inversely associated with self-reported musculoskeletal pain in adulthood . Design Cohort study with baseline data from the Swedish Conscription Register and outcome information from the r and om population -based Swedish Living Conditions Surveys . Setting Sweden , 1970–2005 . Participants 5489 men who at age 17–19 years tested their isometric muscle strength ( h and grip , arm flexion and knee extension ) during the compulsory conscription . Outcome measures The men were surveyed regarding self-reported musculoskeletal pain ; mean follow-up time of 17 ( range 1–35 ) years . Our primary outcome was a self-report of musculoskeletal pain , and secondary outcomes were a report of ‘ severe pain ’ , ‘ pain in back/hips ’ , ‘ pain in neck/shoulders ’ or ‘ pain in arms/legs ’ , respectively . We categorised muscle strength into three groups : low , average and high , using the 25th–75th percentile to define the reference category ( average ) . We estimated relative risks using log binomial regression with adjustment for smoking , body mass index , education and physical activity . Results In the adjusted model , men with low overall muscle strength had decreased risk of self-reported musculoskeletal pain ( 0.93 , 95 % CI 0.87 to 0.99 ) . We observed no such association in men with high strength ( 0.99 , 0.93 to 1.05 ) . Furthermore , no statistically significant increase or decrease in risk was observed for any of the secondary outcomes . Conclusions In men , low overall isometric muscle strength in youth was not associated with an increased risk of future musculoskeletal pain . Contrarily , we observed a slightly decreased risk of self-reported musculoskeletal pain in adulthood . Our results do not support a model in which low muscle strength is a risk factor for future musculoskeletal pain This study evaluates the effect of physical activity on the bone content ( BMC ) and density ( BMD ) in 51 girls ( 14.2+/-0.4 yr ) . Twenty-four were placed in the h and ball group as they have been playing h and ball for at least 1 year ( 3.9+/-0.4 ) . The other 27 who did not perform in any kind of regular physical activity other than that programmed during the compulsory physical education courses comprised the control group .  Bone mass and areal density were measured by dual-energy X-ray absorptiometry ( DXA ) . The maximal leg extension isometric force in the squat position with knees bent at 90 degrees and the peak force , mean power , and height jumped during vertical squat jump were assessed with a force plate . Additionally , 30-m run ( running speed ) and 300-m run ( as an estimate of anaerobic capacity ) tests were also performed . Maximal aerobic capacity was estimated using the 20-m shuttle-run tests . Compared to the controls , h and ballers attained better results in the physical fitness tests and had a 6 % and 11 % higher total body and right upper extremity lean mass ( all P<0.05 ) . The h and ballers showed enhanced BMC and BMD in the lumbar spine , pelvic region , and lower extremity ( all P<0.05 ) . They also showed greater BMC in the whole body and enhanced BMD in the right upper extremity and femoral neck than the control subjects ( all P<0.05 ) . As expected , total lean mass strongly correlated with total and regional BMC and BMD ( r=0.79 - 0.91 P<0.001 ) . Interestingly , 300-m running speed correlated with BMC and BMD variables ( r=0.59 - 0.67 and r=0.60 - 0.70 , respectively ; all P<0.001 ) . Multiple regression analysis showed that the 30-m running speed test , combined with the height and body mass , has also predictive value for whole-body BMC and BMD ( R=0.93 and R=0.90 , P<0.001 ) . In conclusion , h and ball participation is associated with improved physical fitness , increased lean and bone masses , and enhanced axial and appendicular BMD in young girls . The combination of anthropometric and fitness-related variables may be used to detect girls with potentially reduced bone mass PURPOSE The present population study is conducted to examine the extent to which lifetime physical activity and lifestyle parameters contribute to  bone mass . METHODS The design of the project is a 27-yr prospect i ve follow-up study . Subjects are 126 males gathered from the Leuven Longitudinal Study on Lifestyle , Physical Fitness and Health , and aged 13 yr at the onset of the study and 40 at the end of the follow-up .  Physical activity and lifestyle parameters are obtained with question naires . Bone mass is measured by means of dual-energy x-ray absorptiometry ( DXA ) . RESULTS Results from correlation and regression analyses show that the body mass index ( BMI ) is the most important parameter in relation to cortical and trabecular bone mass at every examination period . Longitudinally , static arm strength , running speed , and upper muscular endurance contribute significantly to the prediction of adult bone mass . The parameter " change in motor fitness " between 18 and 13 yr old was used to control for hereditary influences . The score for static arm strength and trunk muscle strength demonstrates a significant correlation with adult total bone mineral content ( BMC ) and lumbar bone mineral density ( BMD ) , respectively . At the age of 40 , the Baecke sports index is almost equally important as BMI in explaining the variance in BMD , and static arm strength is the most important parameter ( after BMI ) for BMC . CONCLUSION Lifetime physical activity , physical fitness , and BMI all contribute to adult bone mass . The clinical relevance of these findings is emphasized by the fact that the observed patterns of physical activity and motor fitness pertain to customary lifestyle and are thus feasible targets Study Design . This study comprised a cross-sectional part and a prospect i ve part . Objective . To study whether low lumbar extension strength , high lumbar mobility , and high mobility – extension strength ratios are related to current and future low back pain in adolescents . Summary of Background Data . Knowledge is sparse about the significance of lumbar mobility and strength for low back pain in adolescents . Methods . The study population included all the adolescents in the eighth and ninth grade s of a rural municipality ( n = 44 ) and in an urban area ( n = 61 ) during the 1996–1997 school year . At baseline , 88 adolescents ( mean age , 14.7 years ) participated in the study , giving a response rate of 84 % .  Low back pain was assessed by question naire as pain or discomfort in the low back during the preceding year . Sagittal lumbar mobility  was tested by Schober ’s modified technique , and lumbar strength as  static endurance extension strength  . The follow-up part was conducted 3 years later , which included 98 % of the adolescents . Results . By bivariate and multivariate analyses in the cross-sectional part of the study , low back pain was found to be highly associated with low lumbar extension strength ( P = 0.004–0.02 ) , and high lumbar mobility – extension strength ratios ( P = 0.005–0.04 ) . Baseline low lumbar extension strength and high lumbar sagittal mobility – extension strength ratios ( P = 0.03 and P = 0.02 , respectively ) predicted low back pain at follow-up assessment in multivariate analyses when control was used for gender , previous low back pain , physical activity , and well-being . No associations were found between plain sagittal mobility and low back pain . Conclusion . The study findings support theories suggesting insufficient strength and stability in the low back as important factors for both concurrent and future low back pain in adolescents OBJECTIVES We examined the relationship between comprehensive fitness tests and overweight using a school surveillance system in a racially diverse city in the United States . RESEARCH METHODS AND PROCEDURES Trained physical education teachers  measured weight , height , and fitness annually from 2001 to 2003 . We compiled data for a cross-sectional analysis ( 11,845 measurements on 6297 students , 5 to 14 years of age ) and a 1-year prospect i ve analysis ( 4215 measurements on 2927 students not overweight at baseline , 5 to 13 years of age ) . Overweight was defined as a BMI > or = 95th percentile ( Centers for Disease Control and Prevention 2000 growth charts ) , and underfit was defined as failing at least one of five fitness tests : endurance run , abdominal strength , flexibility , upper body strength , and agility ( Amateur Athletic Union and Fitnessgram ) . Associations between fitness and overweight were examined using multivariate logistic regression models , adjusting for sociodemographic status and repeated measurements over time . RESULTS The mean number of fitness tests passed was lower among students with a BMI above the 80th percentile . Overweight incidence over 1 year was 7 % and 2 % for underfit and fit girls , respectively ( odds ratio , 3.3 ; 95 % confidence interval , 2.0 to 5.6 ) . Not passing either the endurance run or upper body strength test was associated with overweight incidence in both boys and girls . After adjusting for baseline BMI , the endurance run remained a significant predictor of incident overweight among girls ( odds ratio , 2.0 ; 95 % confidence interval , 1.1 to 3.5 ) . DISCUSSION Findings support a cross-sectional inverse relationship between physical fitness and  overweight among school-aged children . The direction of causation between fitness and overweight is not clearly established and merits further study Strength training represents an alternative to endurance training for patients with type 2 diabetes . Little is known about the effect on insulin action and key proteins in skeletal muscle , and the necessary volume of strength training is unknown . A total of 10 type 2 diabetic subjects and 7 healthy men ( control subjects )  strength-trained one leg three times per week for 6 weeks while the other leg remained untrained . Each session lasted no more than 30 min . After strength training , muscle biopsies were obtained , and an isoglycemic-hyperinsulinemic clamp combined with arterio-femoral venous catheterization of both legs was carried out . In general , qualitatively similar responses were obtained in both groups . During the clamp , leg blood flow was higher ( P < 0.05 ) in trained versus untrained legs , but despite this , arterio-venous extraction glucose did not decrease in trained legs . Thus , leg glucose clearance was increased in trained legs ( P < 0.05 ) and more than explained by increases in muscle mass . Strength training increased protein content of GLUT4 , insulin receptor , protein kinase B-alpha/beta , glycogen synthase ( GS ) , and GS total activity . In conclusion , we found that strength training for 30 min three times per week increases insulin action in skeletal muscle in both groups . The adaptation is attributable to local contraction-mediated mechanisms involving key proteins in the insulin signaling cascade This study investigates whether physical activity and physical performance in adolescence are positively related to  adult bone mineral density ( BMD ) . In 1974 , physical activity , endurance , and muscular strength were measured in 204 r and omly selected female students , age 16.1 + /- 0.3 year ( range 15 - 17 years ) . Twenty years later , 36 of the women volunteered to undergo a measurement of their BMD . Women who were members in a sports club in adolescence had significantly higher adult BMD ( mean differences of 5 % to 17 % depending on site ) compared with subjects who were not engaged in a sports club . Furthermore , women with persistent weight-bearing activity in adulthood had significantly higher BMD compared with women who had stopped being active or had never been active . The differences ranged between 5 % and 19 % with the highest difference found in trochanter BMD . Stepwise regression analyses showed that membership in a sports club at baseline was a significant independent predictor of BMD in the total body , lumbar spine , legs , trochanter , and femoral neck , explaining 17 - 26 % of the variation in BMD . Change in body weight was a strong independent predictor of BMD of the total body and arms , explaining 8 % of the variation in both sites . In addition , running performance at baseline was an independent predictor of total body BMD , whereas the two-h and lift performance significantly predicted BMD of the total body , legs and trochanter . The hanging leg-lift and h and grip were both significant predictors of arm BMD . In conclusion , membership in a sports club and site-specific physical performance in adolescence together with the change in body weight were significantly associated with adult BMD in premenopausal women Study Design . This was a prospect i ve 3-year follow-up study of r and omized matched subgroups of 15-year-old school children with or without low back pain initially . Objective . In addition to low back pain and leisure time physical activity , spinal mobility , trunk muscle strength , and early degenerative findings of the lumbar spine were evaluated . Summary of Background Data . Reliable epidemiologic studies on the prevalence of low back pain and development of early degenerative changes of the lumbar spine in young persons have been sparse . Along with several other characteristics , the relationship of these changes to frequent low back pain in young persons is not known . Methods . After a question naire-based survey was administered , subjects with or without low back pain were examined initially and at follow-up with special reference to leisure time physical activity , anthropometry , spinal mobility , trunk muscle strength , and magnetic resonance imaging findings of the lumbar spine . Results . At baseline and at follow-up , those subjects with initial low back pain were characterized by a low frequency of physical activity and decreased spinal function . During follow-up , the occurrence of disc degeneration increased significantly more in the original group with low back pain than among asymptomatic subjects . Furthermore , disc degeneration at baseline significantly predicted future frequent low back pain . Initial disc protrusion also predicted future frequent low back pain . Conclusion . After the rapid physical growth period , there seemed to be a causal relationship between the early evolution of the degenerative processes of the lower lumbar discs and frequent low back pain in several subjects OBJECTIVES The mechanical environment is considered to be the most important determinant of bone strength . Local muscle force , in turn , is regarded as the largest source of loading applied to bones . However , the effect of weight-bearing on bone mineral accrual is unclear . Comparing the relationship between muscle force and bone mineral content ( BMC ) in the upper and lower limbs provides a means of investigating this issue . SUBJECTS AND METHODS The study group comprised 258 healthy girls aged 10 - 13 years old at baseline .  BMC , lean body mass ( LM ) and fat body mass ( FM ) of total body were assessed by dual-energy X-ray absorptiometry at baseline and 2 years after . The maximal isometric voluntary contraction ( MVC ) of left elbow flexors and knee extensors was evaluated by a dynamometer . A hierarchical linear statistical model with r and om effects was used to analyze the relationship between BMC and limb-matched MVC . Fisher 's z-transformation was used to compare the correlation coefficients between arms and legs . The ratio of BMC to MVC ( BMC /MVC ) in upper and lower limbs was compared using Student 's t-test . RESULTS BMC was highly correlated with MVC in arms and legs ( r(2)=0.54 and 0.50 , respectively ) , and the correlation coefficients did not differ between upper and lower limbs . On the other h and , BMC /MVC was significantly ( 30 % ) higher in leg than in arm . CONCLUSIONS The results indicate that local muscle contraction and weight-bearing exert an additive effect on bone mass accretion in the lower limbs . Exercise regimes combining resistance and impact training should provide larger bone response than either one of them alone in growing children Purpose Sports have different effects on bone development and effective interventions to improve bone health of adolescent athletes are needed . The purpose of the study was to investigate the effect of a 9-month jumping intervention on bone geometry and metabolism in adolescent male athletes . Methods Ninety-three adolescent ( 14.1 yr old ) male swimmers ( SWI ) , footballers ( FOO ) , and cyclists ( CYC ) were r and omized to intervention and sport ( INT-SWI = 19 , INT-FOO = 15 , and INT-CYC = 14 ) or sport only ( CON-SWI = 18 , CON-FOO = 15 , and CON-CYC = 12 ) groups . Cross-sectional area , cross-sectional moment of inertia ( CSMI ) , and section modulus ( Z ) at the femoral neck were assessed using hip structural analysis and trabecular texture of the lumbar spine using trabecular bone score . Bone mineral content ( BMC ) at femoral neck and lumbar spine was assessed using dual-energy x-ray absorptiometry . Serum N-terminal propeptide of procollagen type I , isomer of the carboxy-terminal telopeptide of type 1 collagen , total serum calcium , and 25-hydroxyvitamin D were analyzed . Results INT-CYC acquired significantly higher lumbar spine BMC ( 4.6 % ) and femoral neck BMC ( 9.8 % ) than CON-CYC . INT-CYC acquired significantly higher cross-sectional area ( 11.0 % ) , CSMI ( 10.1 % ) , and trabecular bone score ( 4.4 % ) than CON-CYC . INT-SWI acquired significantly higher femoral neck BMC ( 6.0 % ) and CSMI ( 10.9 % ) than CON-SWI . There were no significant differences between INT-FOO and CON-FOO in any bone outcomes . N-terminal propeptide of procollagen type I significantly decreased in CON-SWI , INT-FOO , CON-FOO , and CON-CYC . Carboxy-terminal telopeptide of type 1 collagen significantly decreased in CON-SWI and CON-CYC . The 25-hydroxyvitamin D significantly increased in INT-CYC , CON-CYC , INT-FOO , and CON-FOO . Conclusions A 9-month jumping intervention improved bone outcomes in adolescent swimmers and cyclists , but not in footballers . This intervention might be used by sports clubs to improve bone health of adolescent athletes Background Although cardiorespiratory fitness ( CRF ) in childhood and adolescence may be linked to future cardiovascular health , there is currently limited evidence for a longitudinal association . Objectives To provide a systematic review on the prospect i ve association between CRF in childhood and adolescence and cardiovascular disease ( CVD ) risk factors at least 2 years later . Methods Using a systematic search of Medline , Embase , and SPORTD iscus , relevant articles were identified by the following criteria : generally healthy children and adolescents between 3 and 18 years of age with CRF assessed at baseline , and a follow-up period of ≥ 2 years . The outcome measures were CVD risk factors . We appraised quality of the included articles with STROBE and QUIPS checklists . Results After screening 7524 titles and abstract s , we included 38 articles , assessing 44,169 children and adolescents followed up for a median of 6 years . Eleven articles were of high quality . There was considerable heterogeneity in methodology , measurement of CRF , and outcomes , which hampered meta- analysis . In approximately half of the included articles higher CRF in childhood and adolescence was associated with lower body mass index ( BMI ) , waist circumference , body fatness and lower prevalence of metabolic syndrome in later life . No associations between CRF in childhood and adolescence and future waist-to-hip ratio , blood pressure , lipid profile , and glucose homeostasis were observed . Conclusion Although about half of the included articles reported inverse associations between CRF in childhood and adolescence and future BMI , body fatness , and metabolic syndrome , evidence for other CVD risk factors was unconvincing . Many articles did not account for important confounding factors such as adiposity . Recommendations for future research include st and ardizing the measurement of CRF , i.e. by reporting VO2max , using st and ardized outcome assessment s , and performing individual patient data meta-analyses
target: Conclusion A prospect i ve negative association was observed between muscular fitness in childhood/adolescence and adiposity and cardiometabolic parameters in later life , together with a positive association for bone health .
  There is inconclusive evidence for low back pain benefits
background: Background No previous systematic review has quantitatively examined the association between muscular fitness during childhood and adolescence and health parameters later in life .
  Objective The aim was to systematic ally review and meta-analyze the current evidence for a prospect i ve association between muscular fitness in childhood and adolescence and future health status .