The relative decline in MVPA affects both sexes from an early age ; however , it is greater among girls .
Moderate-to-vigorous-intensity  physical activity ( MVPA )  is important for childhood obesity prevention and treatment , yet declines with age .
Timing and magnitude of the decline in MVPA in children and adolescents are unclear but important for informing effective obesity intervention development .
This systematic review aim ed to determine and compare the year-to-year changes in MVPA among children and adolescents .
Physical activity and skills intervention: SCORES cluster randomized controlled trial.
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
The relative decline in MVPA affects both sexes from an early age ; however , it is greater among girls .
Moderate-to-vigorous-intensity  physical activity ( MVPA )  is important for childhood obesity prevention and treatment , yet declines with age .
Timing and magnitude of the decline in MVPA in children and adolescents are unclear but important for informing effective obesity intervention development .
This systematic review aim ed to determine and compare the year-to-year changes in MVPA among children and adolescents .