Impact of Moderate-Intensity and Vigorous-Intensity Physical Activity on Mortality Use of SPARK to promote after-school physical activity. Sustained effects of physical activity on bone health: Iowa Bone Development Study. Changes in physical activity levels, lesson context, and teacher interaction during physical education in culturally and linguistically diverse Australian schools Physical activity growth curves relate to adiposity in adolescents. Effects of a playground marking intervention on school recess physical activity in French children. A Longitudinal Study of the Family Physical Activity Environment and Physical Activity among Youth The impact of a 3-year after-school obesity prevention program in elementary school children. A prospective study of the determinants of physical activity in rural fifth-grade children. The relationship between psychosocial correlates and physical activity in underserved adolescent boys and girls in the ACT trial. Associations of body size and composition with physical activity in adolescent girls. Volume and intensity of physical activity in a large population-based cohort of middle-aged and older Australians: prospective relationships with weight gain, and physical function. Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: the Medical College of Georgia Fitkid Project. A 10-Month Physical Activity Intervention Improves Body Composition in Young Black Boys Using step cadence goals to increase moderate-to-vigorous-intensity physical activity. Relationship between the intensity of physical activity, inactivity, cardiorespiratory fitness and body composition in 7–10-year-old Dublin children Physical activity as a substitute for sedentary behavior in youth Relationships among fitness, body composition, and physical activity. Effect of fitness and physical activity on bone mass in adolescents: the HELENA Study Can we skill and activate children through primary school physical education lessons? "Move it Groove it"--a collaborative health promotion intervention. Physical activity and skills intervention: SCORES cluster randomized controlled trial. Relations of moderate and vigorous physical activity to fitness and fatness in adolescents. School-community partnerships: a cluster-randomized trial of an after-school soccer program.
Purpose Physical activity guidelines recommend at least 150 min of moderate-intensity physical activity ( MPA ) , 75 min of vigorous-intensity physical activity ( VPA ) , or combination of MPA and VPA . However , few epidemiological studies have examined whether the general population can derive equal health benefits from MPA or VPA . This study examined the associations of different activity intensities with mortality . Methods In this prospect i ve cohort study , a total of 83,454 community-dwelling Japanese who answered a question naire in 2000–2003 were followed for all-cause mortality through 2012 . Subjects were classified into four groups by physical activity guidelines and also by the proportion of VPA to total MVPA , that is , physically inactive , physically active without any VPA ( 0 % VPA ) , and active with some VPA ( 30 % or less ) or with more VPA ( more than 30 % ) . Hazard ratios of all-cause mortality were calculated with adjustment for potential confounders including physical activity volume . Results During 894,718 person-years of follow-up , 8891 deaths  were identified . Compared with physically inactive subjects , the adjusted hazard ratios for all-cause mortality were 0.75 ( 95 % confidence interval , 0.68–0.83 ) , 0.73 ( 0.65–0.82 ) , and 0.74 ( 0.62–0.89 ) among men , and 0.71 ( 0.62–0.81 ) , 0.75 ( 0.64–0.88 ) , and 0.74 ( 0.58–0.94 ) among women . For “ 0 % VPA , ” “ 30 % or less ” and “ more than 30 % , ” respectively . Conclusions Meeting the guidelines in either pattern of physical activity is important for lowering mortality risk . It may be suggested that people can receive comparable health benefit by MPA or VPA as long as they meet the guideline BACKGROUND The after-school period is potentially an important venue for increasing physical activity for youth . We sought to assess the effectiveness of the Sports , Play , and Recreation for Youth ( SPARK ) program to increase physical activity and improve cardiorespiratory fitness and weight status among elementary students after school . METHODS This quasi-experimental controlled study compared change in moderate to vigorous physical activity ( MVPA ) , body mass index ( BMI ) z-score , and cardiorespiratory fitness ( VO(2 ) ) over 5 months between students in after-school programs exposed to SPARK versus controls . Participants were fifth grade students at 3 intervention schools ( N = 48 ) and 3 control schools ( N = 52 ) . RESULTS There was no difference between groups in mean change in MVPA , BMI z-score , or cardiorespiratory fitness . After-school time dedicated to physical activity did not increase with the implementation of SPARK . Intervention students ' self- assessment of their activity levels relative to their peers significantly increased compared to control students ( p = .011 ) . CONCLUSIONS In this 5-month study , the SPARK program did not increase MVPA in the after-school setting . Increasing the amount of time dedicated to physical activity may be as important as the curriculum used to effectively increase physical activity after school Studies of youth athletics and interventions have shown some maintenance of bone mineral content ( BMC ; g ) after cessation of training , but less is known about sustained effects of everyday physical activity ( PA ) . Using a prospect i ve cohort , this report examined potential effects of  childhood PA  on  adolescent BMC . Participants ( N=156 boys , 170 girls ) had exams at ages 5 , 13 , and 15 . Body size and maturity were determined using anthropometry . Moderate-to-vigorous-intensity PA ( MVPA ) and vigorous-intensity PA ( Vigorous PA ) were measured using accelerometry .  BMC of the spine and hip was measured using dual-energy X-ray absorptiometry . Mixed regression models tested whether PA at age 5 affected BMC at ages 13 and 15 after adjustment for age ( year ) , height ( cm ) , weight ( kg ) , maturity ( pre-peak height velocity or post ) , and activity level ( min/day ) . Analysis was repeated to control for age 5 BMC . On average , boys participated in 59 , 52 , and 38 min of MVPA and 13 , 17 , and 11 min of Vigorous PA at ages 5 , 13 , and 15 , respectively . MVPA ( β=0.799 ) and Vigorous PA ( β=1.338 ) at age 5 predicted later spine BMC ( p<0.05 ) . MVPA ( β=0.480 ) at age 5 predicted hip BMC . Girls participated in 47 , 33 , and 26 min of MVPA and 10 , 9 and 7 min of Vigorous PA at ages 5 , 13 , and 15 , respectively . Neither MVPA nor Vigorous PA  predicted later spine BMC . MVPA ( β=0.302 ) at age 5 predicted hip BMC . After controlling for BMC at age 5 as well as the other covariates , the effect of MVPA ( β=0.695 ) and Vigorous PA ( β=1.079 ) at age 5 remained significant for boys at the spine . For girls , neither MVPA nor Vigorous PA at age 5 predicted spine or hip BMC . Children 's early PA  appears to have a modest effect on  adolescent BMC at the critical regions of spine and hip ; benefits may be greater for geometric changes , which future studies should include Background Recent data show that only 15 % of Australian adolescents participate in adequate amounts of physical activity ( PA ) and those students from Asian and Middle-Eastern background s in Grade s 6–12 are significantly less active than their English-speaking background peers . Schools have recently been recognised as the most widely used and cost-effective setting for promoting PA among youth and one domain within schools where PA can occur regularly for all youth , regardless of cultural background or socio-economic status , is during physical education ( PE ) . Methods This study describes changes in physical activity ( PA ) , lesson context and teacher interaction in physical education over the first two years in culturally and linguistically diverse secondary schools . Grade 7 PE classes in six schools were r and omly observed using systematic direct observation ( n = 81 ) and then followed up over the same period ( n = 51 ) twelve months later . Results There was no significant decline in moderate-to-vigorous physical activity ( MVPA ) during PE ( MD = −4.8 % ; p = .777 ) , but a significant decline and medium negative effect in time spent in vigorous physical activity ( VPA ) ( MD = −7.9 % ; p = .009 ) during PE was observed . Significant declines and large negative effects over time in percentage of PE time spent in management ( MD = −8.8 % ; p < .001 ) and the number of observations where teachers promoted  PA ( MD = −20.7 % ; p < .001 ) . Conclusions The decline of VPA and teacher promotion of PA in culturally and linguistically diverse schools is of concern . Given the declines in VPA and the increases in time spent in game play , further research is needed to ascertain whether PE instruction could be improved by focussing on skill instruction and fitness in a games-based PE instruction model . Further research for increasing teacher promotion of PA during PE is needed PURPOSE Findings from prospect i ve studies on associations between physical activity and adiposity among youth are inconsistent . Our aim was to describe physical activity trajectories during secondary school and examine the association with change in adiposity in youth . METHODS  Physical activity  was measured in 20 survey cycles from 1999 to 2005 ; anthropometrics were measured in survey cycles 1 , 12 , and 19 . Individual growth curves modeling moderate-to-vigorous physical activity ( MVPA ) and vigorous physical activity ( VPA ) were estimated . Estimates of initial level and rate of decline in MVPA and VPA bouts per week were included as potential predictors of body fat% and body mass index using age- and sex-specific linear regression . RESULTS Complete data were available for 840 and 760 adolescents aged 12 - 13 years at baseline , followed from survey cycles 1 - 12 and 12 - 19 , respectively . Among girls , yearly declines of one MVPA and one VPA bout per week during earlier adolescence were associated with increases of 0.19 ( 95 % confidence interval [ CI ] , 0.02 - 0.36 ) and 0.47 ( 95 % CI , 0.015 - 0.92 ) units of body fat% , respectively . In boys , a yearly decline of one MVPA bout per week was associated with an increase of 0.38 ( 95 % CI , 0.05 - 0.70 ) units of body fat% during later adolescence . CONCLUSIONS Obesity prevention programs should include strategies to prevent declines in physical activity OBJECTIVE Playground interventions offer an opportunity to enhance school recess physical activity . We aim ed to assess the effects of playground marking on objective ly measured school recess physical activity in French children . METHODS Participants were four hundred and twenty children ( 6 - 11years old ) from 4 primary schools in Nord-Pas de Calais , France . Children 's physical activity ( PA ) was measured with a uniaxial accelerometer twice a day ( morning and afternoon recess ) during a 4-day school week in April and May 2009 . Two experimental schools ( EG ) received a recess-based intervention ( playground markings ) and two others served as controls ( CG ) . Percentage of time spent on the following intensities of physical activity during school recess was measured before and after intervention : sedentary ( SED ) , light physical activity ( LPA ) , moderate physical activity ( MPA ) , vigorous physical activity ( VPA ) , very high physical activity ( VHPA ) and moderate-to-vigorous physical activity ( MVPA ) . RESULTS At baseline , school recess PA among children from CG was significantly ( p<0.001 ) higher than that among EG children . No interaction was observed between the recess-based intervention and gender . After the intervention , the EG spent significantly ( p<0.05 ) more time in MPA , VPA and MVPA with a concomitant significant decrease in SED ( p<0.05 ) compared to baseline , while the PA in CG remained unchanged . CONCLUSION Painted playground markings had a positive short-term effect on school recess physical activity levels Purpose . Although the family environment is a potentially important influence on children 's  physical activity ( PA )  , prospect i ve data investigating these associations are lacking . This study aim ed to examine the longitudinal relationship between the family environment and PA among youth . Design . A 5-year prospect i ve cohort study . Setting . Nineteen r and omly selected public schools in Melbourne , Australia . Subjects . Families of 5- to 6-year-old ( n = 190 ) and 10- to 12-year-old ( n = 350 ) children . Measures . In 2001 , parents reported their participation in PA , family-based PA , and support and reinforcement for their child 's PA . In 2001 , 2004 , and 2006 ,  moderate to vigorous intensity PA ( MVPA )  was assessed among youth using accelerometers .  Weekend and “ critical window ” ( after school until 6:00 P.M. ) MVPA were examined because we hypothesized that the family environment would most likely influence these behaviors . Analysis . Generalized estimating equations predicted average change in MVPA over 5 years from baseline family environment factors . Results . Maternal role modeling was positively associated with boys ' critical window and weekend ( younger boys ) MVPA .  Paternal reinforcement of PA  was positively associated with critical window and weekend MVPA among all boys , and paternal direct support was positively associated with weekend MVPA ( older boys ) . Among girls , maternal coparticipation in PA predicted critical window MVPA , and sibling coparticipation in PA was directly associated with weekend MVPA ( younger girls ) . Conclusions . Longitudinal relationships , although weak in magnitude , were observed between the family environment and MVPA among youth . Interventions promoting maternal role modeling , paternal reinforcement of and support for PA , and maternal and sibling coparticipation in PA with youth are warranted . ( Am J Health Promot 2011;25[3]:159–167 . BACKGROUND Children tend to be sedentary during the after-school hours , and this has deleterious effects on their health . The objective of the present study was to determine the effects of a 3-year after-school physical activity ( PA ) program , without restriction of dietary energy intake , on percent body fat ( % BF ) , cardiorespiratory fitness ( CRF ) , and cardiometabolic markers in children . METHODS A cluster r and omization design was employed . A total of 574 3rd grade children from 18 elementary schools in the southeastern United States participated . The intervention consisted of 80 minutes of age-appropriate moderate-to-vigorous PA each school day . The main outcomes of interest were % BF measured by dual-energy X-ray absorptiometry ; CRF measured by heart rate in response to a submaximal step test ; nonfasting total and high-density lipoprotein cholesterol ( HDL-C ) ; and resting blood pressure ( BP ) . RESULTS Intent-to-treat analyses showed significant treatment by time interactions for % BF ( p = 0.009 ) and CRF ( p = 0.0003 ) . The change pattern of the means suggested that % BF and CRF in intervention children improved relative to control children during the school months , rebounding to the levels of control children over the summers following years 1 and 2 . Year-by-year analyses of what occurred during the months when the program was offered revealed dose – response relations for % BF and CRF , such that the clearest beneficial effects were seen for those youth who attended at least 60 % of the after-school sessions . No significant intervention effects were seen for cholesterol or BP . CONCLUSIONS An after-school PA program was effective in reducing adiposity and improving CRF , especially in the children who attended the sessions at least 3 days/week . However , the favorable effects on % BF and CRF were lost over the summer . Thus , it is critical to incorporate strategies that attract and retain the children to receive an adequate dose of PA year-round BACKGROUND Underst and ing the factors that influence physical activity behavior is important in the design of intervention programs targeted at youth . METHODS A prospect i ve study design was used to identify the predictors of vigorous physical activity ( VPA ) ( > or = 6 METs ) and moderate and vigorous physical activity ( MVPA ) ( > or = 3 METs ) among 202 rural , predominantly African-American children . Selected social-cognitive determinants of physical activity were assessed via question naire in the fifth grade . Participation in VPA and MVPA was assessed via the previous day physical activity recall 1 year later in the sixth grade . RESULTS For girls , participation in community sports , self-efficacy in overcoming barriers , enjoyment of school physical education , race ( white > black ) , and perception of mother 's activity level ( active vs inactive ) were significant predictors of VPA . For  MVPA , participation in community sports and self-efficacy in overcoming barriers were significant predictors . For boys , self-efficacy in overcoming barriers was the only significant predictor of VPA , while beliefs regarding activity outcomes and participation in community sports were significant predictors of MVPA . CONCLUSION Social-cognitive constructs such as physical activity self-efficacy , access to community physical activity outlets , and positive beliefs regarding physical activity outcomes are important predictors of future physical activity behavior among rural , predominantly African-American children BACKGROUND Previous research suggests motivation , enjoyment , and self-efficacy may be important psychosocial factors for underst and ing physical activity ( PA ) in youth . While previous studies have shown mixed results , emerging evidence indicates relationships between psychosocial factors and PA may be stronger in boys than girls . This study exp and s on previous research by examining the effects of motivation , enjoyment and self-efficacy on PA in underserved adolescent ( low income , ethnic minorities ) boys and girls . Based on previous literature , it was hypothesized the effects of motivation , enjoyment and self-efficacy on  moderate-to-vigorous PA ( MVPA )  would be stronger in boys than in girls . METHODS Baseline cross-sectional data were obtained from a r and omized , school-based trial ( Active by Choice Today ;  ACT ) in underserved 6th grade rs ( N=771 girls , 651 boys ) . Intrapersonal variables for PA were assessed via self-report and confirmatory factor analyses were conducted for each predictor .  MVPA  was assessed with 7-day accelerometry estimates . RESULTS Multivariate regression analyses stratified by sex demonstrated a significant positive main effect of self-efficacy and motivation on MVPA for girls . Boys also showed a positive trend for the effect of motivation on MVPA . CONCLUSIONS The results from this study suggest motivation and self-efficacy should be better integrated to facilitate the development of more effective interventions for increasing PA in underserved adolescents PURPOSE To examine whether components of body composition ( size , fat mass , and fat-free mass ) were related to physical activity . METHODS A r and om sample of 60 eligible sixth grade girls at each of 36 schools ( six schools per region and six regions in total sample ) ; complete measurements on 1,553 girls .  Physical activity was assessed over 6 d in each girl using an accelerometer , and body composition was assessed using a multiple regression equation using body mass index and triceps skinfold . Minutes of moderate-to-vigorous and vigorous physical activity  were estimated from accelerometer counts per 30 s above threshold values determined from a previous study . RESULTS Significant inverse relationships were found for all measures of body size and composition and all physical activity indices . The combination of fat and fat-free mass expressed as a weight and as an index ( divided by height squared ) along with race , SES , site , and school were most highly associated with physical activity in multiple regression analysis , accounting for 14 - 15 % of the variance in physical activity . Fat mass was more closely related to moderate-to-vigorous physical activity ( MVPA ) and vigorous physical activity ( VPA ) than fat-free mass with higher st and ardized regression coefficients . CONCLUSION We conclude that both fat mass or fat mass index as well as fat-free mass or fat-free mass index make independent contributions in association with physical activity levels . These indices are recommended for future studies OBJECTIVES To examine prospect ively whether higher proportions of vigorous physical activity ( VPA ) , independent of total activity volume , are associated with better outcomes in weight maintenance and physical function . METHODS We used three-year longitudinal data ( 2006/07 - 2009/10 ) of adults 45 and older ( n=32,087 ; 59.5±9.3years ) from New South Wales , Australia . Logistic regression models examined odds of weight gain and functional decline by volume and intensity of physical activity . RESULTS On average , body weight increased by 0.66 kg ( SD=5.83 , p<0.001 ) ; a vali date d physical function score ( MOS-PF ) decreased by 4.79 ( SD=12.56 , p<0.001 ) . There was a 10 % reduction in the odds of weight gain for participants who reported 300min/week or more of moderate to vigorous physical activity ( MVPA ) compared to less than 150min of MVPA . The proportion of MVPA that was vigorous was not associated with weight change . With the physical functioning outcome , there were independent protective effects from volume and intensity of physical activity . Independent of total MVPA , each 1 % increase in the proportion of total activity that was vigorous was associated with a 0.3 % decrease in the odds of decline in physical function . CONCLUSION These prospect i ve findings indicate that VPA per se plays an important role in the prevention of functional decline OBJECTIVE To evaluate the effect of a 3-year after-school physical activity ( PA ) intervention on aerobic fitness and percent body fat ( % BF ) . METHODS In total , 18 schools were r and omized into intervention or control arms . Measurements were made at the beginning and end of the third , fourth and fifth grade s. Fitness was measured with heart rate response to a bench-stepping task.%BF and bone density were measured with dual-energy x-ray absorptiometry . The intervention included 40 min of academic enrichment activities , during which healthy snacks were provided , and 80 min of moderate-to-vigorous PA ( MVPA ) . RESULTS Data analyses were performed on 206 youths who remained in the same schools for the 3-year period , who were measured at all six time points and , for the intervention group , who attended at least 40 % of the sessions in each of the 3 years . The group by time interactions were significant for fitness ( p < 0.01 ) and % BF ( p < 0.05 ) . Children in intervention schools improved in fitness and % BF during the school years and returned to levels similar to those in control schools during the summers . Over the six measurement points , the intervention group increased more than the control group in bone density ( p < 0.01 ) , fat-free soft tissue ( p < 0.01 ) , weight ( p < 0.01 ) , height ( p < 0.01 ) , and body mass index ( p < 0.05 ) . CONCLUSIONS An after-school program focusing on MVPA had a beneficial effect on fitness and body composition . During the summers , the beneficial effect of the previous year 's participation on fitness and % BF was lost . This highlights the importance of year-round programs to promote healthy growth in youths Objective . To determine if a 10-month after-school physical activity ( PA ) intervention could prevent deleterious changes in body composition and cardiovascular ( CV ) fitness in young black boys . Methods . Following baseline measures , 106 boys ( 8–12 yrs ) were r and omized to either a control group or an intervention group , further divided into attenders ( ATT ) and nonattenders ( NATT ) , participating in ≥60 % or < 60 % of the intervention , respectively . The daily intervention consisted of skills development ( 25 min ) , vigorous PA ( VPA , 35 min ) , and strengthening/stretching ( 20 min ) components . Body composition was measured by dual-energy X-ray absorptiometry . Results . Following the intervention , the ATT exhibited an increase in moderate-to-vigorous PA and a significant reduction in BMI , fat mass , and % BF compared to the control group . A significant association among the intervention energy expenditure and changes in body composition and CV fitness was observed only in the ATT group . Conclusion . An after-school PA program of sufficient length and intensity can promote healthy changes in body composition and fitness levels in black boys who attend at least 3 days/week BACKGROUND Increasing moderate-to-vigorous-intensity physical activity ( MVPA ) is an important public health goal . Pedometers are evidence -based devices for increasing daily activity , but studies have not evaluated the comparative efficacy of step cadence goals for increasing MVPA . PURPOSE This study aim ed to evaluate the efficacy of three pedometer-based step goals for increasing MVPA . METHODS Latina women ( n = 180 ; 18 - 55 yr , mean body mass index = 31.1 , SD = 6.5 ) were recruited to 12 community centers , which were r and omly assigned to one of three conditions . Each group received an identical 12-wk theory-based physical activity ( PA ) intervention that differed only on the type of daily step goal : 1 ) a self-selected goal ( SELF ) ; 2 ) a goal of 10,000 steps per day ( FREQUENCY ) ; or 3 ) a goal of 3000 steps in 30 min ( CADENCE ) . Accelerometer-based PA  was measured at baseline and after 12 wk . RESULTS Adjusted multilevel pattern-mixture models using generalized estimating equations revealed that participants in the CADENCE condition engaged in similar levels of postintervention MVPA to those in the SELF and FREQUENCY goal conditions . However , MVPA of participants in the CADENCE condition was more likely to occur in bouts lasting greater than 10 consecutive minutes compared with the MVPA of participants in the SELF ( P = 0.01 ) or FREQUENCY ( P = 0001 ) conditions . CONCLUSIONS PA interventions should consider including a step cadence goal to help individuals accumulate bout-based MVPA and meet national PA guidelines Objective : To investigate the relationships between the time spent in specific intensities of activity and inactivity ,  cardiorespiratory fitness and body composition in children . Methods : A cross-sectional study was conducted in a r and om sample of schools . Height , weight and waist circumference were measured in 224 children aged 7–10 years . Cardiorespiratory fitness was estimated by the 20 m multistage running test , and physical activity was measured over 4 days by the RT3 ( a triaxial accelerometer ) . Time each day spent in moderate and vigorous intensities of activity was calculated . Results : Twelve schools agreed to participate in the study .  Body composition and fitness data were obtained for 224 children and activity data for 152 children . Boys were found to take part in about twice as much vigorous and hard activity as girls ( mean ( 95 % confidence interval ) 64.3 ( 53.2 to 75.4 ) min in boys compared with 37 ( 33.1 to 40.9 ) min in girls ; p<0.001 ) . In boys there was significant difference between those defined as normal , overweight and obese in the time spent in vigorous activity ( p<0.05 ) , but no such difference was found in girls . A significant negative correlation between waist circumference and time spent in vigorous activity ( r = –0.31 , p<0.05 ) was found in boys but not in girls . Time spent sedentary was positively correlated with waist circumference in boys ( r = 0.33 , p<0.01 ) but not in girls . In both boys and girls there were significant negative correlations between fitness and both body mass index ( r = –0.274 , p<0.001 ) and waist circumference ( boys : r = –0.503 , p<0.01 ; girls : r = –0.286 , p<0.01 ) . Conclusion : In boys , body composition was inversely related to fitness and to vigorous activity and was positively related to inactivity . In girls , body composition was related to fitness but not to specific components of physical activity Background : Youth may choose to be sedentary rather than physically active . Purpose : The purpose of this study was to use behavioral economics methods to investigate how experimental changes in the amount of sedentary behaviors influenced physical activity . Methods : Fifty-eight 8-to 16-year-old youth were studied in a within-subject crossover design with three 3-week phases : baseline , increasing , and decreasing targeted sedentary behaviors by 25 % to 50 % . Results : At baseline , boys were more active than girls ( 518.9 vs. 401.2 accelerometer counts/min , p = .02 ) , and obese youth more sedentary than nonobese youth ( 240.5 vs. 174.4 min/day , p = .003 ) . During the increase sedentary behavior phase , targeted sedentary behaviors increased by 52.1 % , with girls increasing sedentary behaviors more than boys ( 114.7 vs. 79.8 min/day , p = .04 ) . Physical activity decreased ( −48.3 counts/min , p < .01 ) when sedentary behaviors increased , with obese youth decreasing total and moderate to vigorous physical activity ( MVPA ) more than nonobese youth ( −110.4 vs. 8.9 counts/min , p < .001 ; −3.3 vs. −.03%MVPA , p = .013 ) . During the decrease sedentary behavior phase , targeted sedentary behaviors decreased by 55.6 % from baseline as nonobese youth increased physical activity , whereas obese youth decreased physical activity ( 55.8 vs. −48.0 counts/min , p = .042 ; 1.1 vs. −2.1 % MVPA , p = .021 ) . Youth who substituted physical activity when sedentary behaviors were increased had greater st and ardized body mass index ( z-body mass index = 1.4 vs. 0.4 , p = .018 ) , whereas youth who substituted physical activity when sedentary behaviors were decreased were less active at baseline ( 396.1 vs. 513.7 counts/min , p = .035 ) . Conclusions : Behavioral economics provides a methodology to underst and changes in physical activity when sedentary behaviors are modified and to identify factors associated with substitution of physically active for sedentary behaviors PURPOSE This study was design ed to examine the associations of physical activity and body composition with cardiorespiratory fitness in eighth grade girls . METHODS A r and om sample of 1440 eighth grade girls at 36 schools participated in this cross-sectional investigation , which represented an ethnically and geographically diverse group .  Cardiorespiratory fitness was assessed using a modified physical work capacity test on a cycle ergometer that predicted workload at a heart rate of 170 beats.min . Physical activity was assessed over 6 d in each girl using an accelerometer and body composition was estimated from body mass index and triceps skinfolds using a previously vali date d equation . Pearson correlations and multiple regression analyses were used to determine the relationships among fitness , physical activity , and body composition . RESULTS Significant linear relationships among cardiorespiratory fitness , body composition , and physical activity were found . The combination of fat and fat-free mass along with racial group and a race by fat-free-mass interaction accounted for 18 % ( R ) of the variation in physical fitness . Adding moderate-to-vigorous physical activity to the regression model increased the R to 22 % . Black girls had somewhat lower fitness levels ( P < 0.05 ) especially at higher levels of fat and fat-free mass than other racial/ethnic groups . CONCLUSIONS Physical activity , fat-free mass , and the interaction between fat-free mass and racial group are significantly associated with cardiorespiratory fitness in adolescent girls Our aim is to analyse the effect on bone mass of : ( 1 ) physical fitness performance on a specific group of physical activity ( PA ) and , ( 2 ) PA on a specific physical fitness performance group . Bone mineral content ( BMC ) by dual energy X-ray absorptiometry ( DXA ) and PA by accelerometers was assessed in 373 Spanish adolescents ( 182 males ) . Adolescents were classified as : active and non-active ( ≥60 or < 60 min day−1 of moderate-vigorous PA ) . Fitness was assessed through speed/agility , strength and cardiorespiratory tests . Adolescents were classified by tertiles ( T1 , T2 and T3 ) . ANCOVA was used for the analysis with sex , height , lean mass , calcium intake and pubertal status as covariates . Adolescents with lower strength , speed/agility and cardiorespiratory fitness ( CRF ) showed lower BMC in the whole body and extremities compared with adolescents with better results in these tests , mainly those non-active adolescents . Non-active adolescents with high fitness levels showed higher BMC ( whole body and upper limbs ) than active ones . The conclusions included : ( 1 ) within the non-active group , lower levels of fitness were associated with lower BMC ; this might be through PA or trough an effect of PA on muscle mass . ( 2 ) Non-active adolescents with high level of fitness in most fitness tests showed higher BMC than their active peers , in spite of their lower PA levels . These unexpected results could be influenced by several factors such as genetics , nutrition , type of exercise or sport , hormones and skeletal age BACKGROUND Physical education ( PE ) lessons are an ideal setting to improve child fundamental movement skills ( FMSs ) and increase physical activity ( PA ) for optimal health . Despite this , few studies have assessed the potential to do both simultaneously . The " Move It Groove It " primary school intervention in New South Wales , Australia , had this opportunity . METHODS A whole school approach to implementation included establishment of school project teams , a teacher " buddy " system , project Web site , teacher training workshops , and small grants for equipment . The quasi-experimental evaluation involved 1,045 year 3 and 4 children ( aged 7 to 10 years ) in nine intervention and nine control rural primary schools ( 53 % boys/47 % girls ) . It utilised pre- and postobservational surveys of ( 1 ) mastery or near mastery levels for each of eight FMSs , ( 2 ) proportion of PE lesson time spent in moderate to vigorous PA ( MVPA ) and vigorous PA ( VPA ) , and ( 3 ) teacher- and lesson-related context ual covariates . Data were analysed by hierarchical logistic multiple regression . RESULTS For FMSs , overall mastery or near mastery level at baseline was 47 % ranging from 22.7 % for the overarm throw among girls to 75.4 % for the static balance among boys . The intervention delivered substantial improvements in every FMS for both genders ranging from 7.2 % to 25.7 % ( 13 of 16 comparisons were significant ) . For PA level , mean MVPA at baseline was 34.7 % . Baseline MVPA for boys was 38.7 % and for girls was 33.2 % . The intervention was associated with a nonsignificant 4.5 % increase in MVPA and a significant 3.0 % increase in VPA . This translates to a gain of < 1 minute of MVPA per average 21-minute lesson . CONCLUSIONS This is the first study to show that by modifying existing PE lessons , significant improvements in FMS mastery can be gained without adversely affecting children 's MVPA and VPA . To increase PA levels , we recommend increasing the number of PE lessons per week PURPOSE  Physical activity ( PA  ) declines dramatically during adolescence , and activity levels are consistently lower among children living in low-income communities . Competency in a range of fundamental movement skills ( FMS ) may serve as a protective factor against the decline in PA typically observed during adolescence . The purpose of this study was to evaluate the effect of a 12-month multicomponent PA and FMS intervention on children attending primary schools in low-income communities . METHODS The Supporting Children 's Outcomes using Rewards , Exercise , and Skills intervention was evaluated using a cluster r and omized controlled trial . The sample included 25 classes from eight primary schools located in low-income communities . Participants were 460 children ( 54.1 % girls ) age 8.5 ± 0.6 yr . Primary outcomes were objective ly measured PA ( ActiGraph GT3X and GT3X+ accelerometers ) , FMS competency ( Test of Gross Motor Development 2 , six locomotor and six object control skills ) , and cardiorespiratory fitness ( 20-m multistage fitness test ) assessed at baseline , midprogram ( 6-months ) , and at posttest ( 12 months ) . Linear mixed models , adjusted for sex , age , body mass index z-score , socioeconomic status , ethnicity , and school class as a r and om factor , were used to assess the effect of the intervention . RESULTS At midprogram , there were no significant intervention effects for any of the outcomes . At posttest ( study 's primary time point ) , there were intervention effects for daily moderate-to-vigorous PA ( MVPA ) ( adjusted mean difference , 12.7 min·d of MVPA ; 95 % confidence interval ( CI ) , 5.0 - 20.5 ) , overall FMS competency ( 4.9 units ; 95 % CI , -0.04 to 9.8 ) , and cardiorespiratory fitness ( 5.4 laps ; 95 % CI , 2.3 - 8.6 ) . CONCLUSIONS A school-based multicomponent PA and FMS intervention maintained daily MVPA , improved overall FMS competency , and increased cardiorespiratory fitness among children attending primary schools in low-income communities 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 IMPORTANCE Identifying community-based programs that increase physical activity among diverse youth could yield sustainable tools to reduce obesity and obesity disparities . OBJECTIVE To evaluate the impact of a community-based after-school soccer and youth development program , America SCORES , on students ' physical activity , weight status , and fitness . DESIGN Cluster-r and omized trial . Study measures were collected in the fall ( baseline ) , winter ( midpoint ) , and spring ( end point ) of the 2009 - 2010 school year . SETTING After-school programs in 6 schools within a large urban school district . PARTICIPANTS All 4th and 5th grade students in after-school programs at the study schools were eligible . INTERVENTION Three schools were r and omized to receive the SCORES after-school program , delivered via the train-the-trainer model . MAIN OUTCOME MEASURES Change in minutes of after-school moderate-to-vigorous physical activity ( MVPA ) , fitness ( maximal oxygen consumption ) , and body mass index over 1 school year . RESULTS Participants ( n = 156 ) were diverse ( 42 % Latino , 32 % Asian , and 12 % African American ) and 76 ( 49 % ) had a body mass index at or above the 85th percentile . There were no significant group differences in the change in physical activity , fitness , or weight status among all students . However , among students with a body mass index at or above the 85th percentile , SCORES significantly increased MVPA after school ( 3.4 min/d ; 95 % CI , 0.3 - 6.5 ) and on Saturdays ( 18.5 minutes ; 95 % CI , 3.4 - 33.6 ) . CONCLUSIONS AND RELEVANCE Existing community-based programs such as SCORES can increase physical activity among low-income youth , particularly those most at risk for weight-related comorbidities . While evaluating existing programs presents special challenges , partnerships between communities , schools , and research ers are an important component of translational research to address obesity . TRIAL REGISTRATION clinical trials.gov Identifier : NCT01156103
VPA was more strongly associated with reduced body fat and central adiposity compared with MPA and /or MVPA .
Additionally , VPA was more strongly associated with increased CRF when compared with lower intensities .
Findings were inconclusive between all PA intensity levels and CM biomarkers , and several significant relationships observed for VPA were attenuated when controlling for CRF .
A potential VPA dose is identified as yielding favorable health benefits in adiposity and fitness .
While CM biomarkers were not consistently associated with PA intensity level , the literature suggests VPA may yield health benefits above those received from MPA for reduced adiposity and improved CRF .
Background .
Increasing evidence suggests that vigorous physical activity ( VPA ) in youth may yield greater health benefits than moderate ( MPA ) or moderate-to-vigorous physical activity ( MVPA ) .
The purpose of this review was to assess the relationship between PA intensity and body composition , cardiorespiratory fitness ( CRF ) , and cardiometabolic ( CM ) biomarkers in youth .