Relations of moderate and vigorous physical activity to fitness and fatness in adolescents. Fatness leads to inactivity, but inactivity does not lead to fatness: a longitudinal study in children (EarlyBird 45) Regular participation in sports is associated with enhanced physical fitness and lower fat mass in prepubertal boys Intervening to Reduce Sedentary Behaviors and Childhood Obesity among School-Age Youth: A Systematic Review of Randomized Trials Influence of extracurricular sport activities on body composition and physical fitness in boys: a 3-year longitudinal study A randomized controlled trial of single versus multiple health behavior change: promoting physical activity and nutrition among adolescents. Associations between Physical Activity and Health Parameters in Adolescent Pupils in Egypt Exercise training improves body composition, blood lipid profile and serum insulin levels in obese children. A randomized trial of sequential and simultaneous multiple behavior change interventions for physical activity and fat intake. A comprehensive physical activity promotion programme at elementary school: the effects on physical activity, physical fitness and psychosocial correlates of physical activity. A school-based physical activity program to improve health and fitness in children aged 6–13 years ("Kinder-Sportstudie KISS"): study design of a randomized controlled trial [ISRCTN15360785] Objectively measured physical activity and sedentary time: cross-sectional and prospective associations with adiposity in the Millennium Cohort Study Outcomes of a multifaceted physical activity regimen as part of a diabetes self-management intervention Association between physical activity (PA) guidelines and body composition variables in middle-aged and older women. Effects of Child Care Intervention on Physical Activity and Body Composition. Randomized trial of three strategies to promote physical activity in general practice. Cross-sectional and prospective associations between moderate to vigorous physical activity and sedentary time with adiposity in children
BACKGROUND It is unclear how moderate and vigorous intensities of physical activity ( PA ) are associated with cardiovascular fitness ( CVF ) and percentage of body fat ( % BF ) in adolescents . OBJECTIVE We tested the hypothesis that vigorous PA , to a greater degree than moderate PA , would be associated with better CVF and lower % BF . DESIGN This was a cross-sectional study of 421 black and white high school students ( x age : 16 y ) .  PA was measured with 5 d of accelerometry and expressed in min/d of moderate or vigorous PA .  CVF was measured with a multistage treadmill test and was expressed as the oxygen consumption at a heart rate of 170 bpm . % BF was measured with dual-energy X-ray absorptiometry . Multiple regressions were used to determine the degree to which variance in CVF and % BF was explained by PA , after control for age , sex , race , and the sex x race interaction . RESULTS A higher index for CVF was associated with higher amounts of moderate and vigorous PA ;  more variance was explained by vigorous than by moderate PA .  Lower % BF was associated with higher amounts of vigorous PA but not with the amount of moderate PA . CONCLUSION Black and white adolescents who engaged in relatively large amounts of free-living vigorous exercise were likely to be relatively fit and lean Objective To establish in children whether inactivity is the cause of fatness or fatness the cause of inactivity . Design A non-intervention prospect i ve cohort study examining children annually from 7 to 10 years . Baseline versus change to follow-up associations were used to examine the direction of causality . Setting Plymouth , Engl and . Participants 202 children ( 53 % boys , 25 % overweight/obese ) recruited from 40 Plymouth primary schools as part of the EarlyBird study . Main outcome measures  Physical activity ( PA ) was measured using Actigraph accelerometers . The children wore the accelerometers for 7 consecutive days at each annual time point . Two components of PA were analysed : the total volume of PA and the time spent at moderate and vigorous intensities . Body fat per cent ( BF% ) was measured annually by dual energy x ray absorptiometry . Results BF% was predictive of changes in PA  over the following 3 years , but PA levels were not predictive of subsequent changes in BF% over the same follow-up period . Accordingly , a 10 % higher BF% at age 7 years predicted a relative decrease in daily moderate and vigorous intensities of 4 min from age 7 to 10 years ( r=−0.17 , p=0.02 ) , yet more PA at 7 years did not predict a relative decrease in BF% between 7 and 10 years ( r=−0.01 , p=0.8 ) . Conclusions Physical inactivity appears to be the result of fatness rather than its cause . This reverse causality may explain why attempts to tackle childhood obesity by promoting PA have been largely unsuccessful OBJECTIVE : To study the effect of physical activity on whole body fat ( BF ) , its regional deposition and the influence of body fatness on physical performance in prepubertal children . DESSIGN : Cross-sectional study .SUBJECTS : A total of 114 boys ( 9.4±1.5 y , Tanner I – II ) , r and omly sample d from the population of Gran Canaria ( Spain ) , 63 of them physically active ( PA , at least 3 h per week during the previous year ) and 51 nonphysically active ( non-PA ) .  MEASUREMENTS : Body composition ( DXA ) , anthropometric variables ( body circumferences and skinfolds ) and physical fitness were determined in all subjects . RESULTS : The PA obtained better results in maximal oxygen uptake , isometric leg extension force , vertical jump ( muscular power ) , and 300 m ( anaerobic capacity ) and 30 m running tests ( speed ) than the non-PA . A lower percentage of body fat ( % BF ) ( 4 U less , P<0.05 ) , whole BF mass ( 36 % less , P<0.05 ) and regional fat mass ( 28 , 25 , and 30 % less in the trunk , legs and arms , respectively , all P<0.05 ) was observed in the PA compared to the non-PA . The waist and hip circumferences correlated more closely with both the fat mass accumulated in the trunk region and the % BF ( r=0.81–0.95 , P<0.001 ) than the waist-to-hip ratio ( WHR ) . The WHR correlated with the percentage of the whole fat mass accumulated in the trunk ( PFT ) ( r=0.52–0.53 , P<0.001 ) . In both groups , the PFT increased curvilinearly with the % BF , regardless of the level of physical activity . ANCOVA analysis revealed that total and regional fat masses explained less than 40 % of the difference in performance between the PA and non-PA group . The mean speed in the 30 m running test ( V30 ) , combined with the height and whole body mass , has predictive value for the BF mass ( R=0.98 , P<0.001 ) . The % BF may be estimated from the body mass index ( BMI ) and V30 ( % BF=8.09 + 2.44 · BMI ( kg m−2)–5.8·V30 ( m s−1 ) , R=0.94 , P<0.001 ) in prepubertal boys . CONCLUSIONS : Regular participation in at least 3 h per week of sports activities and competitions on top of the compulsory physical education program is associated with increased physical fitness , lower whole body and trunkal fat mass in prepubertal boys Objective . To assess the effectiveness of interventions that focus on reducing  sedentary behavior ( SB ) among school-age youth and to identify elements associated with interventions ' potential for translation into practice setting s. Methods . A comprehensive literature search was conducted using 4 data bases for peer- review ed studies published between 1980 and April 2011 . R and omized trials , which lasted at least 12 weeks , aim ed at decreasing  SB among children aged 6 to 19 years were identified . Results . Twelve studies were included ; 3 focused only on SB , 1 focused on  physical activity ( PA )  , 6 were combined SB and PA interventions , and 2 studies targeted SB , PA , and diet .  The majority of the studies were conducted in a school setting , while others were conducted in such setting s as clinics , community centers , and libraries . Conclusions . Overall , interventions that focused on decreasing SB were associated with reduction in time spent on SB and /or improvements in anthropometric measurements related to childhood obesity . Several of the studies did consider elements related to the intervention 's potential for translation into practice setting Objective : To analyse the effect of extracurricular physical activities on fat mass accumulation and physical fitness during growth in early pubertal males . Design : Longitudinal study .Subjects : A total of 42 male children ( 9.4±1.4 years , Tanner I – II and 12.7±1.5 years , Tanner III – IV , before and after the 3.3 years follow-up , respectively ) , r and omly sample d from the population of Gran Canaria ( Spain ) , 26 of them physically active ( PA , at least 3 h per week during 3 years ) and 16 non-physically active ( non-PA ) . Measurements : Body composition ( dual-energy X-ray absorptiometry ) , anthropometrics ( body circumferences and skinfolds ) and physical fitness variables ( dynamic and isometric force , anaerobic capacity and maximal aerobic power ) were determined in all subjects . Results : Both groups had comparable body sizes at the start and the end of the study . Body mass index increased with growth more in the PA than in the non-PA group ( P<0.05 ) . However , fat mass accumulation with growth was lower in the PA than in the non-PA ( P<0.05 ) . There was a positive relationship between the increment of total and trunkal fat mass , especially in non-active children ( r 2=0.93 ) . In contrast , there was an inverse relationship between the total lean mass growth and the accumulation of total and regional fat mass ( r=−0.37 to −0.41 , all P<0.05 ) . Physical fitness was maintained in the PA , while it worsened in the non-PA children . Conclusions : Without any dietary intervention , children who regularly participate in at least 3 h per week of sports activities are more protected against total and regional fat mass accumulation . They also increase their total lean and bone mass to a greater extent than children who do not participate in extracurricular sport activities . In addition , PA children maintain their physical fitness during growth , while it deteriorates in the non-PA children Targeting multiple behaviors for change may provide significant health benefits . This study compared interventions targeting physical activity and nutrition ( PAN ) concurrently versus physical activity ( PA ) alone .  Adolescents ( N=138 ) were r and omized to the PAN or PA intervention or control condition ( n=46 per group ) . Primary outcomes were change in PA accelerometer and 3-day dietary recording from baseline to 3-month follow-up . The PAN and PA interventions were efficacious in supporting boys ' ( p<.001 ) but not girls ' ( p=.663 ) PA relative to the control condition . Dietary change was minimal . Although the findings do not reveal a decrement to PA promotion when a nutrition intervention was added , neither do they reveal any additional benefit . More studies comparing single versus multibehavioral interventions are needed Physical activity ( PA ) could be protective against  hypertension  , atherosclerosis , coronary heart disease and cardiovascular disease . This quantitative study assessed the association between a PA intervention and three anthropometric parameters ( weight , body mass index , body fat ) and four physiological parameters ( cholesterol level , systolic blood pressure , diastolic blood pressure , heart rate ) among secondary school pupils ( N = 160 ) in Egypt through the school term . The pupils were r and omised to an intervention group ( 80 pupils ) and controls ( 80 pupils ) . Measurements were obtained for all pupils twice : at baseline ; and then again after three months . The PA intervention programme comprised an ‘ afterschool ’ one hour of moderate exercise three times a week for three months . Both the controls and the intervention pupils attended the ‘ normal ’ exercise schedule provided by the school ; in addition , the intervention group attended afterschool PA programme from about 2–3 o’clock in the afternoon . At baseline , employing pupil ’s BMI , 27.5 % and 28.8 % of the intervention and control pupils respectively were classified as overweight . After three months , the percentage of overweight decreased to 12.5 % in the intervention pupils , while it increased to 37.3 % in the controls . At the end of the three months period , there were significant improvements across most anthropometric and physiological parameters of the intervention pupils when compared with the control children . The correlation coefficient of the improvements for the boys and the girls was 0.97 , indicating clearly that the intervention was having nearly the same beneficial effect for boys and girls . A moderate PA programme for a modest period of 3 months could be effective in maintaining or enhancing pupil ’s anthropometric and physiological parameters in comparison to the controls where there was deterioration in both parameters . Policy makers and secondary schools in Egypt might need to pay more attention to PA programmes conducted on school days , in order to motivate pupils to attend such programmes . There is also an urgent need to look at current PA systems within schools in Egypt in order to assess PA outside school times AIM Increasing prevalence of obesity and related diseases especially in children and adolescent has gained more scientific attention . The present study was conducted to determine the effects of regular exercise on childhood obesity often associated with clinical conditions such as hypertension , dyslipidemia and diabetes already at a young age . METHODS The subjects were 40 obese children at 11 ± 1 years and with Body Mass Index ( BMI ) of at least 30 kg/m2 who volunteered to the study and r and omly classified into exercising and non-exercising control group . Physical load of the exercising group was first determined by the Karvonen protocol after which to the subjects underwent a 12-week aerobic exercise training program primary consisting of walking and jogging exercise . Blood pressure , biochemical cardiovascular risk factors and body composition were assessed before and after the exercise-training period and compared to the non-exercising control group . RESULTS In the exercising group , statistically significant changes were observed in the circumference of forearm , elbow , calf , knee , waist , chest and hip , as well as skin fold thickness of chest , subscapulae , calf , abdomen , suprailiac and leg . Similarly , total cholesterol , triglyceride , LDL , VLDL and insulin levels were found to be lower and HDL levels higher than in the non-exercising control group . CONCLUSION While treating obesity in children , a major emphasis should be directed towards increasing regular physical activity and supported with dietary interventions . By this approach the risk of other chronic diseases often associated with obesity could be minimized thereby improving the quality of life BACKGROUND Major questions remain unanswered about how best to accomplish multiple behavior change . The purpose of this study was to evaluate whether there are differences in successfully changing multiple behaviors in computer-tailored sequential and simultaneous interventions for physical activity ( PA ) promotion and fat intake ( FI ) reduction . METHODS Participants ( N=567 ) were r and omly assigned to receive an intervention for PA and FI simultaneously ; PA at baseline and FI at 3 months ; or FI at baseline and PA at 3 months .  Successful behavior change at 6 months was defined as : > 60 min PA increase and /or 5 % FI reduction . Using multinomial logistic regression the odds ratios of successful behaviors change ( none , PA only , FI only , or both ) were determined for intervention mode , gender , age , BMI and education . RESULTS Overall drop-out was 26 % . There was no behavior change for 20.2 % of participants ; 30.5 % successfully decreased FI ; 15.8 % successfully increased PA ; 33.5 % successfully changed both behaviors . Intervention mode , gender and age were not associated with successful behavior change . Compared to those that did not change any behaviors : participants that successfully changed FI were more likely to be overweight/obese ( OR=1.85 ) ; and participants that successfully changed both behaviors were more likely to be overweight/obese ( OR=2.13 ) and have lower education ( OR=2.46 ) . CONCLUSIONS Success in changing multiple behaviors was not associated with intervention mode ; both simultaneous and sequential interventions can be applied . Being overweight might be an extra motivator to change health behaviors OBJECTIVE To evaluate the effects of a comprehensive physical activity ( PA ) promotion programme in elementary schools on children 's total PA levels , leisure-time PA , physical fitness and psychosocial correlates of PA . DESIGN A pre-test-post-test design over two school years . SETTING AND SUBJECTS Sixteen elementary schools ( 764 children , mean age : 11.2 + /- 0.7 years ) were r and omly assigned to the intervention condition ( n = 8) and the control condition ( n = 8) . The intervention included a health-related physical education programme , an extracurricular PA promotion programme and classroom-based PA education lessons . In the total sample , leisure-time PA , psychosocial correlates of PA and physical fitness were measured using a PA question naire and the Eurofit test battery . In a sub- sample , total PA levels were measured using an accelerometer . RESULTS According to accelerometer data , children 's moderate PA and moderate-to-vigorous PA ( MVPA ) levels decreased less in the intervention schools than in the control schools ( P < 0.01 ) . The average time spent on MVPA decreased by 9 min per day in the intervention schools compared with 33 min per day in the control schools . Children in the intervention schools reported significantly more moderate PA in leisure time than the controls ( P < 0.05 ) . No overall improvement of physical fitness and no effects on the psychosocial correlates of PA were found . CONCLUSIONS The comprehensive PA promotion programme was successful in preventing a decline in children 's  total activity levels . Furthermore , the intervention increased children 's PA engagement in leisure time . Therefore , implementation needs to be encouraged Background Childhood obesity is the result of a long lasting imbalance between energy intake and energy expenditure . A major contributing factor is physical inactivity which is closely linked to bone health , cardiovascular disease risk , fitness and psychological factors . The school seems to provide an excellent setting to enhance levels of  physical activity ( PA ) .  However , there is insufficient data from previous school-based intervention trials on how to enhance overall PA . It is also unknown whether an intervention aim ed at increasing PA is effective in improving the children 's health . The purpose of this paper is to outline the design of a school-based r and omized , controlled trial ( RCT ) aim ing to increase overall PA and to improve fitness and health in 6- to 13-year-old children . Methods / Design 15 schools were r and omized to the intervention ( n = 9 ) or the control ( n = 6 ) group , stratified by geographic region ( urban vs. rural ) and by age ( 1st and 5th grade ) . Participation was given for all children in the intervention group since in this group the intervention was part of the normal school curriculum . The intervention during one academic year consisted of : 1 . two additional physical education classes per week given by trained physical education teachers adding up to a total of five PA classes per week , 2 . short PA breaks ( 2–5 min each ) during academic lessons , 3 . PA home work , and 4 . adaptation of recreational areas around the school . All children underwent  anthropometric measurements , blood pressure assessment , fitness testing , measurement of PA  and they filled out question naires . At least 70 % of all children agreed to blood sampling and measurements of body composition and bone mineral measurements by dual energy x-ray absorptiometry . The primary endpoints of the study after one year were an increase in total PA by accelerometry , an increase in aerobic fitness measured by the 20 m shuttle run , a decrease in percent body fat derived from skinfold measurements and an increase in quality of life as assessed by the child health question naire in the intervention group compared to the control group . Secondary outcomes were overall fitness , differences in body composition including body fat distribution , cardiovascular risk factors , psychosocial health , bone mineral content and density of femur , lumbar spine and total body and food intake . Discussion Our preliminary data suggest that the children were representative of Swiss children with respect to sex , socio-demographic status , and body mass index . Short-term results can be expected by the beginning of 2007 . We hypothesized that our intervention will lead to an increase in PA , fitness and overall health . Based on our data , we aim to provide important information regarding the influence of such an intervention on these outcome measures in school-aged children and to provide nationwide guidelines to improve PA in children Objective To examine whether physical activity ( PA ) and sedentary time ( ST ) in primary school-aged children are associated with adiposity at the start of secondary school , and whether these associations differ by sex or ethnic group . Design Nationally representative prospect i ve cohort study . Setting Children born across the UK , between 2000 and 2002 . Participants 6497 singleton children . Outcome measures Measures of adiposity ( body mass index ( BMI ) , fat mass index ( FMI ) and fat free mass index (FFMI))—obtained at 7 and 11 years . Explanatory measures  Total daily PA ( mean counts per minute ( cpm ) ) ; minutes of moderate-to-vigorous PA ( MVPA ) ; and ST .  All assessed at 7 years using accelerometers . Results In cross-sectional analyses , total PA was inversely associated with FMI ( 3.7 % ( 95 % CI 2.7 % to 4.7 % ) reduction per 150 cpm increase ) , as was MVPA ( 4.2 % ( CI 3.2 % to 5.2 % ) reduction per 20 min/day increase ) . Associations were stronger in black and South Asian ethnic groups . Total PA and MVPA were not associated with FFMI . ST was positively associated with FMI ( 1.3 % ( CI 0.2 % to 2.3 % ) increase per 50 min/day increase ) and inversely associated with FFMI ( 0.5 % ( CI 0.2 % to 0.7 % ) reduction per 50 min/day increase ) . Longitudinally , MVPA at age 7 years remained inversely associated with FMI at age 11 years ( 1.5 % ( CI 0.4 % to 2.6 % ) reduction per 20 min/day increase ) . No association was found between total PA and ST and any of the later adiposity measures . Conclusions 7-year-old children who are more physically active are less likely to be obese at that age and at age 11 years . These associations were particularly evident in children from black or South Asian ethnicity at age 7 years and in boys at age 11 years . Measurements of fat mass provide valuable insights into ethnic differences in associations between adiposity and activity Background :  Physical activity ( PA )  is important for management of diabetes , yet practical interventions that achieve sustained behavior change are rare . Purpose : The goals of this research were to evaluate the effectiveness of a multifaceted PA intervention for people with type 2 diabetes that emphasized participant choice in activity selection . Baseline activity patterns were examined to determine whether they predicted changes in PA at 2 months . Methods : Three hundred thirty-five participants were recruited from 42 primary care physicians and then r and omized to either a computer-assisted , tailored self-management intervention ( N = 174 ) or health risk appraisal with feedback control ( N = 161 ) . Primary outcome measures included the Community Healthy Activities Model Program for Seniors Question naire , diet , and psychosocial assessment s at baseline and 2 months . Results : For 301 participants who completed the 2-month follow-up , the intervention significantly improved all PA ( p < .01 ) and moderate PA ( metabolic equivalents > 3.0 , p < .01 ) relative to controls . Baseline cluster analyses grouped participant activity patterns into three categories . At 2 months , cluster assignment differentially predicted change in calories expended in moderate , rote , sport , and lifestyle PA . Conclusions : A computer-assisted , multifaceted approach to PA demonstrated improvement after 2 months . The results suggest that individuals are capable of adjusting their activity patterns to maximize their PA The aim of this study was to investigate the association between volume and frequency of moderate-intensity PA and step-based recommendations and individual body composition variables . Our cohort included 167 healthy ambulatory women ( mean age 62.8 ± 4.8 years ; body mass index [ BMI ] 27.3 ± 4.2 kg/m(2 ) ) who carried out daily activities while wearing the ActiGraph GT1 M accelerometer over a seven day period .  Measurements of BMI , body fat mass index ( BFMI ) , fat-free mass index ( FFMI ) , waist-hip ratio ( WHR ) and visceral fat area ( VFA ) were obtained by the InBody 720 multifrequency bioelectrical impedance analysis ( MFBIA ) device . The significant relationship ( r(s)=0.66 ; p<0.05 ) was found between moderate PA and steps per day . Moderate PA ( r(2)=0.03 - 0.06 ) and steps per day ( r(2)=0.05 - 0.20 ) were significantly associated with observed body composition parameters . Women spending > 300 min/week in moderate PA showed significantly lower values of BFMI ( p=0.02 ) than those who spent 150 - 300 min/week . Carrying out moderate PA for 30 min 5 days a week was significantly associated with lower BMI ( p=0.04 ; η(2)=0.02 ) , BFMI ( p=0.02 ; η(2)=0.03 ) and VFA ( p=0.03 ; η(2)=0.03 ) . In addition , higher amounts of daily steps were significantly associated with lower BMI ( p=0.00 ; η(2)=0.16 ) , BFMI ( p=0.00 ; η(2)=0.21 ) , VFA ( p=0.00 ; η(2)=0.20 ) and WHR ( p=0.00 ; η(2)=0.13 ) . A clear association was found between the generally recommended PA guidelines and body composition variables for the women examined in this study . However , the concept of 10,000 steps/day appears to be the strongest predictor of health-related body composition values INTRODUCTION This study evaluated whether intervening with child care providers would increase physical activity ( PA )  and reduce adiposity in preschoolers . METHODS This was a two-arm , parallel group , cluster RCT whereby six child care centers were r and omly assigned in equal numbers to intervention ( n=40 children ) or control ( n=43 children ) . Participants were aged 3 - 5 years and attended licensed child care centers . Child care providers received two 3-hour train-the-trainer workshops and a training manual at program initiation aim ed at increasing structured and unstructured PA through active play . Control child care centers implemented their st and ard curriculum .  PA and sedentary behavior were measured by accelerometry , and body composition was measured using bioelectrical impedance at baseline and 6 months . Data were collected in 2011 - 2012 and analyzed in April 2015 . RESULTS Linear mixed-effects modeling showed that at 6 months , children in the intervention group demonstrated greater increases in minutes per preschool day spent in overall PA ( 22.5 minutes , 95 % CI=8.9 , 36.1 , p=0.002 ) , and light-intensity PA ( 16.1 minutes , 95 % CI=5.2 , 26.7 , p=0.004 ) , but changes between groups in moderate to vigorous PA did not differ . The intervention group showed greater reductions in body fat percentage ( -1.9 % , 95 % CI=-3.5 , -0.3 , p=0.023 ) and fat mass ( -0.3 kg , 95 % CI=-0.7 , -0.1 , p=0.018 ) , but groups did not differ on fat-free mass , BMI , or z- BMI . CONCLUSIONS Provider-led intervention in child care centers increased preschoolers '  PA and reduced adiposity , therefore may represent a viable approach to promoting PA and related health benefits in preschool-aged children . TRIAL REGISTRATION This study is registered at www . clinical trials.gov NCT02293278 OBJECTIVE To evaluate three strategies for promoting physical activity ( PA ) in a primary care setting . METHOD Data were collected between 2002 and 2004 from 136 patients attending two general practice s in Brisbane , Australia . Inactive patients ( 50 - 70 years ) were r and omly allocated to one of three hierarchical intervention groups : the general practitioner ( GP ) group received ' brief ' advice ; the GP+ES group also received behavior change advice from an exercise scientist ( ES ) ; and the GP+ES+P group also received a pedometer .  Self-reported PA and its determinants were measured at baseline and weeks 12 and 24 . Cardio-respiratory variables were measured at baseline and week 12 . RESULTS Overall , mean PA time increased by 84 and 128 min/week at weeks 12 and 24 ( p<.01 ) with no significant group differences . Small improvements in blood pressure and post-exercise heart rate were observed . At week 24 , the GP+ES+P group were more likely to report meeting PA guidelines than the GP group ( OR=2.39 95 % CI : 1.01 , 5.64 ) . CONCLUSION PA levels can be increased in mid- to older-age adults , either by brief advice from motivated GPs alone , or from collaboration between GPs and ESs . The most intense intervention ( GP+ES+P ) showed the most promising results Background : Physical activity ( PA ) and sedentary time ( SED ) have both been suggested as potential risk factors for adiposity in children . However , there is paucity of data examining the temporal associations between these variables . Objective : This study aim ed to analyze the cross-sectional and prospect i ve associations between PA , SED and body composition in children . Methods : A total of 510 children ( age at baseline 10.1±0.8 , age at follow-up 11.8±0.9 ) from six Portuguese schools from the Oeiras Municipality participated in this study .  PA and SED were measured by accelerometry and trunk fat mass ( TFM ) and body fat mass ( BFM )  were measured by dual energy X-ray absorptiometry .  Fat mass index ( FMI ) was calculated as BFM divided by height squared . Several regression models adjusted for age , sex , maturity status , follow-up duration , baseline levels of the outcome variable and SED or moderate to vigorous PA ( MVPA ) were performed . Results : MVPA ( min per day ) was cross-sectionally inversely associated with adiposity indexes ( FMI , TFM and BFM ) . Adiposity indexes were inversely associated with time in MVPA . In prospect i ve analyses , MVPA was associated with a lower levels of FMI ( β=−0.37 , 95 % confidence interval ( CI ) : −0.49 to −0.26 , P<0.001 ) , TFM ( β=−0.20 , 95 % CI : −0.29 to −0.10 , P<0.001 ) and BFM ( β=−0.37 , 95 % CI : −0.49 to −0.26 , P<0.001 ) . When the model was adjusted for age , sex , maturity status and for baseline levels of the outcome variables MVPA remained a significant predictor of lower adiposity indexes ( FMI : β=−0.09 , 95 % CI : −0.16 to −0.01 , P<0.05 ; TFM : β=−0.08 , 95 % CI : −0.15 to −0.01 , P<0.05 ; BFM : β=−0.07 , 95 % CI : −0.15 to 0.00 , P<0.05 ) . Adiposity was not associated  with MVPA when modeled as the exposure in prospect i ve analyses . SED was not related with adiposity indexes , except for the relationship with FMI . Conclusions : In cross-sectional and prospect i ve analyses , MVPA is associated with lower adiposity independent of covariates and SED . Results suggest that promoting MVPA is important for preventing gain in adiposity in healthy children
Question naires were the more predominant way to evaluate PA .
Most studies showed that PA promotes a protective effect against a higher BF gain .
CONCLUSION It was concluded that PA has a protective effect against BF with differences between the genders and according to the BF marker or measurement assessed ; higher intensity PA leads to a greater effect against BF gain in both genders ; and the maintenance or increase of PA level on BF observed through analysis of change in PA level yielded more consistent findings in the relation between PA and BF
BACKGROUND Physical activity ( PA ) practice has been inversely associated to body  fat ( BF ) and recommended as a way to reduce and prevent obesity .
The objective of this study was to conduct a systematic review on the association of  PA and BF in adolescence .