The relative influence of demographic, individual, social, and environmental factors on physical activity among boys and girls Development of an Accelerometer-Linked Online Intervention System to Promote Physical Activity in Adolescents Personal and social-environmental correlates of objectively measured physical activity in Norwegian pre-adolescent children. Secular and longitudinal physical activity changes in population‐based samples of children and adolescents School physical education: effect of the Child and Adolescent Trial for Cardiovascular Health. Weekend and weekday patterns of physical activity in overweight and normal-weight adolescent girls. Using Ecological Momentary Assessment to Understand Where and With Whom Adults’ Physical and Sedentary Activity Occur Out and about: association of the built environment with physical activity behaviors of adolescent females. Physical Activity in Children Attending Preschools Gender differences in objectively assessed physical activity in asthmatic and non-asthmatic children. Objectively measured physical activity level and sedentary behavior in Norwegian children during a week in preschool☆ Association between bone stiffness and nutritional biomarkers combined with weight-bearing exercise, physical activity, and sedentary time in preadolescent children. A case-control study. Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults Effectiveness of a 12-month randomized clinical trial to increase physical activity in multiethnic postpartum women: results from Hawaii's Nā Mikimiki Project. Cross-sectional and prospective associations between sleep, screen time, active school travel, sports/exercise participation and physical activity in children and adolescents Neighborhood socioeconomic status and non school physical activity and body mass index in adolescent girls. Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning Organizing “Play Streets” during school vacations can increase physical activity and decrease sedentary time in children Time spent in sedentary behavior and changes in childhood BMI: a longitudinal study from ages 9 to 15 years Developmental Trajectories of Physical Activity, Sports, and Television Viewing During Childhood to Young Adulthood: Iowa Bone Development Study. The Patterns of Moderate to Vigorous Physical Activity and Physical Education Enjoyment Through a 2-Year School-Based Program. Physical activity, sedentary behavior, and adiposity in English children. Physical activity and femoral neck bone strength during childhood: the Iowa Bone Development Study.
Background This study aim ed to evaluate the associations of selected demographic , individual , social , and environmental factors with moderate-to-vigorous physical activity ( MVPA ) in a sample of children and adolescents . Methods  MVPA  was assessed among youth ( n = 294 ) 10 - 17-years-old using the ActiGraph accelerometer . Youth completed measures of demographic and individual variables related to physical activity ( PA ) , perceived social support by parents and peers , and perceived neighborhood characteristics . Parents completed the long-form of the International Physical Activity Question naire . The Physical Activity and Media Inventory was used to measure the home environment and Geographical Information Systems software was used to measure the physical neighborhood environment . Bivariate correlations and hierarchical multiple regression were conducted stratified by gender . Results Boys participated in significantly more MVPA than girls . In hierarchical analyses , peer support , home PA equipment , and temperature were significantly associated with MVPA among boys whereas distance to the school they attended was associated with MVPA among girls . The final models accounted for 25 % and 15 % of the variance in MVPA among boys and girls , respectively . Conclusions Important differences exist among the individual , social , and environmental factors related to MVPA between boys and girls . Boys ' levels of activity appear to be influenced by factors closely linked to unstructured and social types of activities whereas girls ' activities relate to internal and external barriers as well as their proximity to their schools . The prospect i ve contribution of these important individual , social , and environmental factors to changes in MVPA among children and adolescents remains to be determined Most adolescents do not achieve the recommended levels of moderate-to-vigorous physical activity ( MVPA ) , placing them at increased risk for a diverse array of chronic diseases in adulthood . There is a great need for scalable and effective interventions that can increase MVPA in adolescents . Here we report the results of a measurement validation study and a preliminary proof-of-concept experiment testing the impact of Zamzee , an accelerometer-linked online intervention system that combines proximal performance feedback and incentive motivation features to promote MVPA . In a calibration study that parametrically varied levels of physical activity in 31 12 - 14 year-old children , the Zamzee activity meter was shown to provide a valid measure of MVPA ( sensitivity in detecting MVPA = 85.9 % , specificity = 97.5 % , and r = .94 correspondence with the benchmark RT3 accelerometer system ; all p < .0001 ) . In a subsequent r and omized controlled multi-site experiment involving 182 middle school-aged children assessed for MVPA over 6 wks , intent-to-treat analyses found that those who received access to the Zamzee intervention had average MVPA levels 54 % greater than those of a passive control group ( p < 0.0001 ) and 68 % greater than those of an active control group that received access to a commercially available active videogame ( p < .0001 ) . Zamzee ’s effects on MVPA did not diminish significantly over the course of the 6-wk study period , and were statistically significant in both females and males , and in normal- vs. high- BMI subgroups . These results provide promising initial indications that combining the Zamzee activity meter with online proximal performance feedback and incentive motivation features can positively impact MVPA levels in adolescents The aim of this study was to examine modifiable biological , psychological , behavioral and social-environmental correlates of physical activity among 1129 Norwegian 11-year-old children within a cross-sectional sample from the HEalth In Adolescents study .  Physical activity was assessed by accelerometer , and weight and height were measured objective ly . Age- and gender-specific cut-off points proposed by the International Obesity Task Force were used to define body mass index . Social-environmental variables were self-reported by question naire . Hierarchical regression ( linear mixed models ) revealed that normal weight children scored higher on percentage daily moderate-to-vigorous physical activity [ % daily moderate to vigorous physical activity ( MVPA ) ] than overweight/obese children ( P<0.001 ) . Self-efficacy ( P<0.01 ) and perceived social support from friends ( P<0.01 ) were positively associated with children 's % daily MVPA , and a negative association was found for computer/game-use on weekends ( P<0.01 ) . A moderator effect of weight category ( normal vs overweight/obese ) in the relationship between computer/game-use on weekends and % daily MVPA was detected ( P<0.05 ) , reflecting that higher computer/game-use on weekends was associated with lower % MVPA among the overweight/obese , but not among the normal weight . Modifiable correlates from multiple domains accounted for 14 % of the variance in % daily MVPA . Prospect i ve and intervention studies are needed to examine whether these factors act as mediators for physical activity change in pre-adolescent children The aims of this study were to investigate whether  physical activity ( PA ) and sedentary time ( ST )  in 9- and 15-year-olds differed between 2005 - 2006 and 2011 - 2012 ( secular change ) , and to investigate changes in PA and ST from age 9 to 15 ( longitudinal change ) . In 2005 - 2006 , we invited nationally representative sample s of Norwegian 9- ( n=1470 ) and 15-year-olds ( n=1348 ) to participate . In 2011 - 2012 , we invited a new nationally representative sample of 9-year-olds ( n=1945 ) , whereas 15-year-olds ( n=1759 ) were invited to participate either based on previous participation in 2005 - 2006 or from a r and om sample of schools . We assessed PA and ST objective ly using accelerometers . In 2011 - 2012 , both 9- and 15-year-olds spent more time sedentary ( ≥35.7 min/d , P<.001 ) and less time in light PA ( ≥35.2 min/d , P<.001 ) compared to their peers in 2005 - 2006 . Nine-year-old girls also spent less time in moderate-to-vigorous PA ( MVPA ) ( 4.2 min/d , P=.041 ) . In both age groups , the proportion accumulating an average of 60 min/d of MVPA did not differ between the two cohorts . From age 9 to 15 , girls and boys decreased their time spent in LPA ( ≥106.7 min/d , P<.001 ) and in MVPA ( ≥20.8 min/d , P<.001 ) . During the same period , ST increased by a mean of > 2 h/d ( P<.011 ) . We observed an adverse secular change in PA from 2005 - 2006 to 2011 - 2012 among 9- and 15-year-olds , and a large decline in PA in the participants followed longitudinally from age 9 to 15 years BACKGROUND Physical inactivity is a risk behavior for cardiovascular and other diseases . Schools can promote public health objectives by increasing physical activity among youth . METHODS The Child and Adolescent Trial for Cardiovascular Health ( CATCH ) was a multicenter , r and omized trial to test the effectiveness of a cardiovascular health promotion program in 96 public schools in four states . A major component of CATCH was an innovative , health-related physical education ( P+ ) program . For 2.5 years , r and omly assigned schools received a st and ardized PE intervention , including curriculum , staff development , and follow-up . RESULTS Systematic analysis of 2,096 PE lessons indicated students engaged in more moderate-to-vigorous physical activity ( MVPA ) in intervention than in control schools ( P = 0.002 ) . MVPA during lessons in intervention schools increased from 37.4 % at baseline to 51.9 % , thereby meeting the established Year 2000 objective of 50 % . Intervention children reported 12 more min of daily vigorous physical activity ( P = 0.003 ) and ran 18.6 yards more than control children on a 9-min run test of fitness ( P = 0.21 ) . CONCLUSIONS The implementation of a st and ardized curriculum and staff development program increased children 's  MVPA in existing school PE classes in four geographic and ethnically diverse communities . CATCH PE provides a tested model for improving physical education in American schools OBJECTIVE To describe the patterns ( specifically comparing weekdays and weekends classified by intensities ) of  physical activity ( PA ) measured by accelerometry in adolescent girls . RESEARCH METHODS AND PROCEDURES Healthy sixth grade girls ( n=1603 ) , 11 to 12 years old , were r and omly recruited from 36 schools participating in the Trial of Activity in Adolescent Girls . Age , ethnicity , socioeconomic status , weight , and height were taken .  PA patterns were measured for 6 days using accelerometry . RESULTS Adolescent girls spend most of their time in  sedentary  ( 52 % to 57 % of the day ) and  light activity ( 40 % to 45 % of the day ) on weekdays and weekends . In all girls , total PA  comprised 44.5 % of the day ( 41.7 % light , 2.2 % moderate , and 0.7 % vigorous ) with sedentary activity comprising 55.4 % .  Moderate-to-vigorous PA ( MVPA )  was higher ( p<0.001 ) on weekdays than weekends in all girls , but  MVPA  was lower in at-risk of overweight+overweight girls ( p<0.001 ) on both weekdays and weekends compared with normal-weight girls . DISCUSSION Adolescent girls are more active at moderate and vigorous intensities on weekdays than on weekends , and at-risk of overweight and those overweight spend less time engaging in  MVPA  than normal-weight girls Purpose This study used Ecological Momentary Assessment ( EMA ) , a real-time self-report strategy , to describe the physical and social context s of adults ’ physical activity and sedentary activity during their everyday lives and to determine whether these patterns and relationships differ for men and women . Methods Data from 114 adults were collected through mobile phones across 4 days . Eight electronic EMA surveys were r and omly prompted each day asking about current activities ( e.g. , physical or sedentary activity ) , physical and social context s , and perceived outdoor environmental features ( e.g. , greenness/vegetation , safety , and traffic ) . All participants also wore accelerometers during this period to objective ly measure moderate-to-vigorous physical activity ( MVPA ) and sedentary activity . Results Home was the most common physical context for EMA-reported physical and sedentary activity . Most of these activities occurred when participants were alone . When alone , the most commonly EMA-reported physical activity and sedentary activity was walking and reading/using computer , respectively . When in outdoor home locations ( e.g. , yard and driveway ) women demonstrated higher levels of MVPA , whereas men demonstrated higher levels of MVPA when in outdoor park setting s ( ps < .05 ) . Men but not women demonstrated higher levels of MVPA in setting s with a greater degree of perceived greenness and vegetation ( p < .05 ) . Conclusions The current study shows how EMA via mobile phones and accelerometers can be combined to offer an innovative approach to assess the context s of adults ’ daily physical and sedentary activity . Future studies could consider utilizing this method in more representative sample s to gather context -specific information to inform the development of physical activity interventions Locational data , logged on portable GPS units and matched with accelerometer data , was used to examine associations of the built environment with physical activity and  sedentary behaviors of adolescent females . In a sample of 293 adolescent females aged 15 to 18 years old in Minneapolis and San Diego , the built environment around each GPS point and its corresponding sedentary , light , and moderate-to-vigorous intensity physical activity was examined using r and om intercept multinomial logistic regression models . The odds of higher physical activity intensity ( 3-level outcome : sedentary , light , MVPA ) were higher in places with parks , schools , and high population density , during weekdays , and lower in places with more roads and food outlets . Underst and ing the places where physical activity and sedentary behaviors occur appears to be a promising strategy to clarify relationships and inform policy aim ed at increasing physical activity and reducing sedentary behaviors OBJECTIVE : To identify correlates of objective ly measured moderate and vigorous physical activity ( MVPA ) in children during preschool attendance . METHODS : This cross-sectional study included data from 426 apparently healthy Danish children ( 49.5 % boys ) , 5 to 6 years of age enrolled in 42 r and omly selected preschools . The percentage of time spent in MVPA ( ≥574 counts/15 second ) during preschool attendance was measured using ActiGraph accelerometers over 4.3 preschool days in May and June in 2009 . Thirty-seven potential correlates across the child , preschool staff , and preschool environment domains were tested for associations with MVPA . RESULTS : The final multivariate model identified 9 significant correlates of MVPA . Preterm birth , vegetation on the playground , and rainy days were negatively associated with MVPA , whereas child motor coordination , location of preschool building on the playground , gender ( boys ) , percentage afternoon hours , and size of indoor area per child were positively associated with MVPA . The direction of the significant association with the parental mean education level was unclear . CONCLUSIONS : We identified a number of new modifiable correlates  of MVPA  during preschool attendance . The positive association with size of indoor area per child and location of the preschool building on the playground seem important correlates to be targeted in future studies OBJECTIVE To compare objective ly assessed physical activity  levels , between asthmatic children and non-asthmatic controls . METHODS From a r and om community sample of 794 children aged 8 - 9 years , in a case-control design , 104 children with ever doctor 's diagnosis of asthma and 99 non-asthmatic controls were recruited and had assessment of physical activity with biaxial accelerometers for 7 days . RESULTS Children with active ( also reporting at least one episode of wheezing in the last 12 months ) and inactive ( no wheezing in past 12 months ) asthma appeared to have similar physical activity and sedentary activity levels compared to non-asthmatic children . However , girls with active asthma had significantly lower moderate-to-vigorous physical activity ( MVPA ) levels than their peers with adjusted geometric mean ratio of 0.59 ( 95 % CI : 0.369 , 0.929 , P-value = 0.024 ) . No difference in physical and sedentary activity levels was observed between asthmatic and non-asthmatic boys . The difference between genders in the comparison of MVPA levels in asthmatics and controls was statistically significant ( P-value of likelihood ratio test [ LRT ] for effect modification by gender = 0.034 ) . CONCLUSIONS Unlike boys , girls with active asthma appear to be less active than their healthy peers , and this gender difference might explain the inconsistent evidence from previous reports on physical activity levels in asthmatic children . Further studies are needed to confirm the gender interaction in the childhood asthma-physical activity relation and the implication s on current guidelines for physical exercise prescriptions in asthmatic children Although many studies have reported on  physical activity ( PA ) levels using accelerometers , a thorough description of the PA pattern in preschool children during their stay in the preschool , is lacking in the current literature . Furthermore , there remains a lack of underst and ing of the PA level and pattern in children in the lower end of the PA continuum . The first aim of this study was therefore to describe the PA pattern during a week-long stay in a preschool in all children born in 2011 ( either three or four-year-olds ) attending public preschools in a municipality in Norway . The second aim was to describe the PA level and pattern of the children who are the least physically active . This cross-sectional study included baseline data from 95 % of children ( N = 111 ) participating in a r and omized controlled physical activity intervention ( Active Kindergarten – Active Children study ) . The participants wore an Actigraph accelerometer , in week 39 in 2015 , from when they arrived at the preschool on Monday morning and throughout their stay of five consecutive days . The amount of moderate- to vigorous-intensity PA ( MVPA ) per day ranged from 16 min to 116 min , and sedentary time ranged from 2.7 h to 6.5 h per day in the least and most sedentary child , respectively . The least physically active 25 % of children were less active throughout the entire day , and only a few of them managed to achieve the recommended level of MVPA on any weekday . The physical activity levels and patterns among the least active children described in this study may help to inform interventions targeting this group Physical activity ( PA ) and micronutrients such as calcium ( Ca ) , vitamin D ( 25OHD ) , and phosphate ( PO ) are important determinants of skeletal development . This case-control study examined the association of these nutritional biomarkers and different PA behaviours , such as habitual PA , weight-bearing exercise ( WBE ) and sedentary time ( SED ) with bone stiffness ( SI ) in 1819 2 - 9-year-old children from the IDEFICS study ( 2007 - 2008 ) .  SI was measured on the calcaneus using quantitative ultrasound .  Serum and urine Ca and PO and serum 25OHD were determined . Children 's sports activities were reported by parents using a st and ardised question naire . A sub sample of 1089 children had accelerometer-based PA data ( counts per minute , cpm ) . Moderate-to-vigorous PA ( MVPA ) and SED were estimated . Children with poor SI ( below the 15th age-/sex-/height-specific percentile ) were defined as cases ( N=603 ) . R and omly selected controls ( N=1216 ) were matched by age , sex , and country . Odds ratios ( OR ) for poor SI were calculated by conditional logistic regression for all biomarkers and PA behaviour variables separately and combined ( expressed as tertiles and dichotomised variables , respectively ) . ORs were adjusted for fat-free mass , dairy product consumption , and daylight duration . We observed increased ORs for no sports ( OR=1.39 , p<0.05 ) , PA levels below 524 cpm ( OR=1.85 , p<0.05 ) and MVPA below 4.2 % a day ( OR=1.69 , p<0.05 ) compared to WBE , high PA levels ( < 688 cpm ) and high MVPA ( 6.7 % ) , respectively . SED was not associated with SI . ORs were moderately elevated for low serum Ca and 25OHD . However , biomarkers were not statistically significantly associated with SI and did not modify the association between PA behaviours and SI . Although nutritional biomarkers appear to play a minor role compared to the osteogenic effect of PA and WBE , it is noteworthy that the highest risk for poor SI was observed for no sports or low MVPA combined with lower serum Ca ( < 2.5 mmol/l ) or lower 25OHD ( < 43.0 nmol/l ) Background Accelerometers can obtain precise measurements of movements during the day . However , the individual activity pattern varies from day-to-day and there is limited evidence on measurement days needed to obtain sufficient reliability . The aim of this study was to examine variability in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees . Methods We included control participants ( n = 135 ) from the Take a St and ! Intervention ; a cluster r and omized controlled trial conducted in 19 offices .  Sitting time and physical activity were measured using an ActiGraph GT3X+ fixed on the thigh and data were processed using Acti4 software . Variability was examined for sitting time , st and ing time , steps and time spent in moderate-to-vigorous physical activity ( MVPA ) per day by multilevel mixed linear regression modelling . Results Results of this study showed that the number of days needed to obtain a reliability of 80 % when measuring sitting time was 4.7 days for work and 5.5 days for leisure time . For physical activity at work , 4.0 days and 4.2 days were required to measure steps and MVPA , respectively . During leisure time , more monitoring time was needed to reliably estimate physical activity ( 6.8 days for steps and 5.8 days for MVPA ) . Conclusions The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time . The domain specific variability is of great importance to research ers and health promotion workers planning to use objective measures of sedentary behaviour and physical activity . Trial registration Clinical trials NCT01996176 OBJECTIVE Few postpartum ethnic minority women perform leisure-time moderate-to-vigorous physical activity ( MVPA ) . The study tested the effectiveness of a 12-month tailored intervention to increase MVPA in women with infants 2 - 12months old . METHODS From 2008 to 2011 , women ( n=311 ) with infants ( average age=5.7months ) from Honolulu , Hawaii were r and omly assigned to receive tailored telephone calls and access to a mom-centric website ( n=154 ) or access to a st and ard PA website ( n=157 ) . MVPA was measured at baseline , 6 , and 12months using self-report and acclerometers . RESULTS Controlling for covariates , the tailored condition significantly increased self-reported MVPA from an average of 44 to 246min/week compared with 46 to 156min/week for the st and ard condition ( p=0.027 ) . Mothers with≥2 children had significantly greater increases in MVPA in response to the tailored intervention than those with one child  ( p=0.016 ) . Accelerometer-measured MVPA significantly increased over time ( p=0.0001 ) , with no condition differences . There was evidence of reactivity to initially wearing accelerometers ; the tailored intervention significantly increased MVPA among women with low baseline accelerometer MVPA minutes , but not among those with high minutes ( pinteraction=0.053 ) . CONCLUSION A tailored intervention effectively increased MVPA over 12months in multiethnic women with infants , particularly those with more than one child Background The aim of this study was to investigate how sleep , screen time , active school travel and sport and /or exercise participation associates with moderate-to-vigorous physical activity ( MVPA ) in nationally representative sample s of Norwegian 9- and 15-y-olds , and whether these four behaviors at age nine predict change in MVPA from age nine to 15 years . Method We pooled cross-sectional accelerometer and question naire data  from 9- ( n = 2366 ) and 15-y-olds ( n = 1554 ) that participated in the first ( 2005/06 ) and second ( 2011/12 ) wave of the Physical Activity among Norwegian Children Study to investigate cross-sectional associations . To investigate prospect i ve associations , we used data from a sub- sample that participated in both waves ( at age nine and 15 years , n = 517 ) . Results Cross-sectional analyses indicated a modest , inverse association between screen time and MVPA among 9- ( − 2.2 min/d ( 95 % CI : -3.1 , − 1.3 ) ) and 15-y-olds ( − 1.7 min/d ( 95 % CI : -2.7 , − 0.8 ) ) . Compared to their peers with 0–5 min/d of active travel to school , 9- and 15-y-olds with ≥16 min/d accumulated 7.2 ( 95 % CI : 4.0 , 10.4 ) and 9.0 ( 95 % CI : 3.8 , 14.1 ) more min/d of MVPA , respectively . Nine-y-old boys and 15-y-olds reporting ≥8 h/week of sports and /or exercise participation accumulated 14.7 ( 95 % CI : 8.2 , 21.3 ) and 17.9 ( 95 % CI : 14.0 , 21.8 ) more min/d of MVPA , respectively , than those reporting ≤2 h/week . We found no cross-sectional association between sleep duration and MVPA in either age group . None of the four behaviors predicted change in MVPA from age nine to 15 years ( p ≥ 0.102 ) . Conclusion Active travel to school and sport/exercise participation may be important targets for future interventions aim ed at increasing MVPA in children and adolescents . However , future studies are needed to determine causality BACKGROUND Socioeconomic status ( SES ) has well known associations with a variety of health conditions and behaviors in adults but is unknown in adolescents . METHODS Multilevel analysis was conducted to examine the associations between individual and neighborhood-level measures of SES and physical activity and body mass index in a sample of 1554 6th grade girls selected at r and om from 36 middle schools across 6 geographic regions in the United States that participated in the Trial of Activity for Adolescent Girls ( TAAG ) . Data on parental education and employment , and receipt of subsidized school lunch were collected by question naire . Neighborhood-level SES was measured by the Townsend Index . Nonschool physical activity levels were measured by accelerometer and type , location and context was measured using a 3 day physical activity recall ( 3DPAR ) . RESULTS After controlling for race , lower parental education and higher levels of social deprivation were associated with higher BMI . In a model with both variables , effects were attenuated and only race remained statistically significant . None of the indices of SES were related to  accelerometer measured physical activity . Bivariate associations with self-reported Moderate-Vigorous Physical Activity ( MVPA ) location and type ( 3DPAR ) varied by SES . CONCLUSION Among adolescent girls in the TAAG Study , the prevalence of overweight is high and inversely related to individual and neighborhood SES Abstract Recent attention has highlighted the importance of reducing sedentary time for maintaining health and quality of life . However , it is unclear how changing sedentary behavior may influence executive functions and self-regulatory strategy use , which are vital for the long-term maintenance of a health behavior regimen . The purpose of this cross-sectional study is to examine the estimated self-regulatory and executive functioning effects of substituting 30 min of sedentary behavior with 30 min of light activity , moderate-to-vigorous physical activity ( MVPA ) , or sleep in a sample of older adults . This study reports baseline data collected from low-active healthy older adults ( N = 247 , mean age 65.4 ± 4.6 years ) recruited to participate in a 6 month r and omized controlled exercise trial examining the effects of various modes of exercise on brain health and function . Each participant completed assessment s of  physical activity self-regulatory strategy use ( i.e. ,  self-monitoring , goal - setting , social support , reinforcement , time management , and relapse prevention )  and executive functioning . Physical activity and sedentary behaviors  were measured using accelerometers during waking hours for seven consecutive days at each time point . Isotemporal substitution analyses were conducted to examine the effect on self-regulation and executive functioning should an individual substitute sedentary time with light activity , MVPA , or sleep . The substitution of sedentary time with both sleep and MVPA influenced both self-regulatory strategy use and executive functioning . Sleep was associated with greater self-monitoring ( B = .23 , p = .02 ) , goal - setting ( B = .32 , p < .01 ) , and social support ( B = .18 , p = .01 ) behaviors . Substitution of sedentary time with MVPA was associated with higher accuracy on 2-item ( B = .03 , p = .01 ) and 3-item ( B = .02 , p = .04 ) spatial working memory tasks , and with faster reaction times on single ( B = −23.12 , p = .03 ) and mixed-repeated task-switching blocks ( B = −27.06 , p = .04 ) . Substitution of  sedentary  time with sleep was associated with marginally faster reaction time on mixed-repeated task-switching blocks ( B = −12.20 , p = .07 ) and faster reaction time on mixed-switch blocks ( B = 17.21 , p = .05 ) , as well as reduced global reaction time switch cost ( B = −16.86 , p = .01 ) . Substitution for light intensity physical activity did not produce significant effects . By replacing sedentary time with sleep and MVPA , individuals may bolster several important domains of self-regulatory behavior and executive functioning . This has important implication s for the design of long-lasting health behavior interventions . Trial Registration clinical trials.gov identifier NCT00438347 A Play Street is a street that is reserved for children ’s safe play for a specific period during school vacations . It was hypothesized that a Play Street near children ’s home can increase their moderate- to vigorous-intensity physical activity ( MVPA ) and decrease their sedentary time . Therefore , the aim of this study was to investigate the effect of Play Streets on children ’s MVPA and sedentary time .  A nonequivalent control group pretest-posttest design was used to determine the effects of Play Streets on children ’s MVPA and sedentary time . Data were collected in Ghent during July and August 2013 . The study sample consisted of 126 children ( 54 from Play streets , 72 from control streets ) . Children wore an accelerometer for 8 consecutive days and their parents fill out a question naire before and after the measurement period . During the intervention , streets were enclosed and reserved for children ’s play . Four-level ( neighborhood – household – child – time of measurement ( no intervention or during intervention ) ) linear regression models were conducted in MLwiN to determine intervention effects . Positive intervention effects were found for sedentary time ( β = -0.76 ± 0.39 ; χ2 = 3.9 ; p = 0.05 ) and MVPA ( β = 0.82 ± 0.43 ; χ2 = 3.6 ; p = 0.06 ) . Between 14h00 and 19h00 , MVPA from children living in Play Streets increased from 27 minutes during normal conditions to 36 minutes during the Play Street intervention , whereas control children ’s MVPA decreased from 27 to 24 minutes . Sedentary time from children living in the Play Street decreased from 146 minutes during normal conditions to 138 minutes during the Play Street intervention , whereas control children ’s sedentary time increased from 156 minutes to 165 minutes . The intervention effects on MVPA ( β = -0.62 ± 0.25 ; χ2 = 6.3 ; p = 0.01 ) and sedentary time ( β = 0.85 ± 0.0.33 ; χ2 = 6.6 ; p = 0.01 ) remained significant when the effects were investigated during the entire day , indicating that children did not compensate for their increased MVPA and decreased sedentary time , during the rest of the day . Creating a safe play space near urban children ’s home by the Play Street intervention is effective in increasing children ’s MVPA and decreasing their sedentary time Objective : To determine if time spent in objective ly measured sedentary behavior is associated with a change in body mass index ( BMI ) between ages 9 and 15 years , adjusting for moderate-to-vigorous physical activity ( MVPA ) . Design : Prospect i ve observational study of children at ages 9 ( 2000 ) , 11 ( 2002 ) , 12 ( 2003 ) and 15 years ( 2006 ) .  Longitudinal quantile regression was used to model the influence of predictors on changes at the 10th , 25th , 50th , 75th and 90th BMI percentiles over time . Subjects : Participants were enrolled in the National Institute of Child Health and Human Development ( NICHD ) Study of Early Child Care and Youth Development and include both boys and girls ( n=789 ) . Measurements : Objective ly measured BMI ( kg m–2 ) was the outcome variable and objective ly measured sedentary behavior was the main predictor . Adjustment was also made for MVPA , gender , race , maternal education , hours of sleep and healthy eating index . Results : Increases in BMI were observed at all percentiles , with the greatest increase observed at the 90th BMI percentile . Spending more time in sedentary behavior  ( h per day ) was associated with additional increases in BMI at the 90th , 75th and 50th BMI percentiles , independent of MVPA and the other covariates ( 90th percentile=0.59 , 95 % confidence interval ( 95 % CI ) : 0.19–0.98 kg m–2 ; 75th percentile=0.48 , 95 % CI : 0.25–0.72 kg m–2 ; and 50th percentile=0.19 , 95 % CI : 0.05–0.33 kg m–2 ) . No associations were observed between sedentary behavior and changes at the 25th and 10th BMI percentiles . Conclusion : Sedentary behavior was associated with greater increases in BMI at the 90th , 75th and 50th BMI percentiles between ages 9 and 15 years , independent of MVPA . Preventing an increase in sedentary behavior from childhood to adolescence may contribute to reducing the number of children classified as obese IMPORTANCE The diverse developmental patterns of obesogenic behaviors during childhood and adolescence can be better understood by using new analytic approaches to assess the heterogeneity in variation during growth and development and to map the clustering of behavior patterns . OBJECTIVES To identify distinct trajectories of daily time spent in  moderate- to vigorous-intensity physical activity ( MVPA )  from ages 5 to 19 years and to examine the associations of MVPA trajectories with sports participation and television viewing trajectories . DESIGN , SETTING , AND PARTICIPANTS Cohort members in the prospect i ve population -based Iowa Bone Development Study participated in  MVPA assessment s via accelerometry from September 16 , 1998 , to December 9 , 2013 , at ages 5 , 8 , 11 , 13 , 15 , 17 , and 19 years and completed a question naire every 6 months on sports participation and daily time spent in television viewing . MAIN OUTCOMES AND MEASURES Trajectories of MVPA ( minutes per day ) , participation in organized sports ( yes or no ) , and television viewing time ( hours per day ) . RESULTS Based on the data from 537 participants ( 50.1 % females ; 94.6 % white ) , we identified 4 MVPA trajectories : consistently inactive ( 14.9 % ) , consistently active ( 18.1 % ) , decreasing moderate physical activity ( 52.9 % ) , and substantially decreasing high physical activity ( 14.1 % ) . All participants in the consistently inactive trajectory also followed a trajectory of no participation in sports . The consistently active trajectory was associated with decreasing an already low television viewing trajectory ( P < .001 ) . CONCLUSIONS AND RELEVANCE This study provided a nuanced look at the known decrease in MVPA during childhood and adolescence . Sports participation could be a critical way to avoid the consistently inactive pattern . Most important , we identified a subset of participants who maintained a seemingly healthy level of MVPA from childhood to young adulthood . The developmental pathways of physical activity and television viewing behaviors could be related . Additional studies should examine the determinants and health consequences of these specific MVPA trajectories BACKGROUND In this study , we examined the development of children 's moderate to vigorous physical activity ( MVPA ) and physical education ( PE ) enjoyment through the Physical Activity as Civil Skill Program 2012 - 2014 . METHODS Participants were 661 ( 265 intervention , 396 control ) elementary school children in central and northeast Finl and . The program was implemented across 2 years with 3 measurement phases using self-reported MVPA and PE enjoyment , and accelerometer-determined  MVPA  of a r and om sub sample ( N = 76 ) . RESULTS The proportion of children meeting the current MVPA guidelines declined from 38 % to 22 % ( intervention ) and 14 % to 9 % ( control ) , whereas PE enjoyment was stable in both groups . Boys were more physically active than girls only within control group children . Teachers ' feedback indicated that violence and bullying among intervention students reduced during the program , which can be considered as an additional benefit . CONCLUSIONS It may be that both  MVPA  and  PE  enjoyment may require more tailored actions to be increased across a long-term program . It is important to ensure that school-based physical activity programs , especially including transition from elementary to middle school level , provide all children positive experiences , and thus , may improve their motivation , and  MVPA  participation during school days and leisure time BACKGROUND The importance of variation in total volume of physical activity or moderate- to vigorous-intensity physical activity ( MVPA ) to development of body fatness in childhood is unclear , and it is unclear if physical activity has a greater influence on adiposity in boys than girls . PURPOSE To assess relationships between 2-year changes in objective ly measured physical activity , sedentary behavior , and adiposity in English children . METHODS Prospect i ve cohort study , set in Northeast Engl and , of a socioeconomically representative sample of 403 children . Measures were change in accelerometer-determined physical activity and sedentary behavior  from age 7 to 9 years ( data collected 2006/2007 and 2008/2009 ; analyzed in 2010 ) and concurrent change in adiposity ( fat mass index derived from bioelectric impedance ) and change in BMI Z-score . RESULTS Decline in MVPA was associated with a greater increase in fat mass index in boys but not girls . Declining MVPA was associated with increased BMI Z-score in boys but not girls . Increased sedentary behavior was not associated with increased BMI Z-score in either gender . CONCLUSIONS Avoiding mid-late childhood reductions in MVPA may reduce excessive fat gain , although such strategies may have greater impact on boys than girls Structural adaptations of bone to changing mechanical loads have recently been documented during adolescence . However , little is known about how bone adapts structurally during the earlier years . Using a longitudinal observational design spanning 6 years of growth ( age range 4 to 12 years ) , we investigated associations between everyday physical activity and hip geometry in a cohort of healthy Midwestern children ( n=468 ) . Femoral neck ( FN ) cross sectional area ( CSA , cm(2 ) ) and FN section modulus ( Z , cm(3 ) ) were used to describe hip geometry . CSA and Z , indices of axial and bending strength , were assessed using dual-energy X-ray absorptiometry ( DXA ) scans and the hip structure analysis ( HSA ) program . Moderate and vigorous physical activity ( MVPA ) was assessed using accelerometry-based activity monitors and calculated as the number of minutes > or = 3000 accelerometry movement counts . Data were analyzed using multilevel ( r and om- and fixed-effects ) regression models with adjustment for age ( year ) , height ( cm ) , and weight ( kg ) or lean mass ( kg ) . For boys and girls , MVPA was a positive independent predictor of CSA and Z ( p<0.05 ) . On average , children who participated in 40 min of MVPA per day would be expected to have 3 % to 5 % greater CSA and Z than peers participating in 10 min of MVPA per day . Ten-minute increases in daily MVPA had similar effects on CSA in girls and Z in boys as did each additional 1 kg of body weight . When lean mass was substituted for weight , MVPA continued to be a positive independent predictor of CSA and Z for boys , but not girls . This study demonstrates that everyday amounts of physical activity in children are associated with indices of FN bone strength during childhood . Differences in lean mass mediate associations between physical activity and hip geometry in girls , but only somewhat in boys . These results suggest that physical activity is an important contributor to bone strength prior to adolescence and that increasing levels of physical activity during childhood are likely to enhance optimal bone strength
MVPA in children/adolescents with chronic disease appear to be well below guideline recommendations , although comparable with activity levels of their healthy peers except for children with malignancies .
CONTEXT Moderate-to-vigorous physical activity ( MVPA ) and sedentary time ( ST )  are important for child and adolescent health .
OBJECTIVE To examine habitual levels of accelerometer measured MVPA and ST  in children and adolescents with chronic disease , and how these levels compare with healthy peers .