24685956
OBJECTIVE	To investigate the effect of a 9-month physical activity intervention on cardiorespiratory fitness and adiposity among prepubertal children .
METHODS	Prepubertal children ( 8 - to 9-year-olds , N = 220 , 103 girls ) were randomly assigned to a 9-month physical activity intervention or a control group .
METHODS	The intervention provided 70 minutes ( 5 days/week ) of moderate to vigorous physical activity .
METHODS	Maximum oxygen consumption ( Vo2max percentile ) and dual-energy radiograph absorptiometry measured cardiorespiratory fitness and adiposity , respectively .
METHODS	Intention-to-treat analysis was performed to assess baseline and follow-up cardiorespiratory fitness , percentage fat mass ( % FM ) , percentage central fat mass ( % CFM ) , and estimated visceral adipose tissue ( VAT ) area .
RESULTS	The intervention group increased in cardiorespiratory fitness ( 5.4 th percentile ; 95 % confidence interval [ CI ] , 1.8 to 8.9 ) and decreased in % FM ( -0.7 % ; 95 % CI , -1.1 to -0.4 ) and % CFM ( -1.3 % ; 95 % CI , -1.9 to -0.7 ) .
RESULTS	Reductions in % FM were evident for both nonoverweight ( -0.62 % ; 95 % CI , -1.07 to -0.17 ) and overweight or obese ( -0.86 % ; 95 % CI,-1 .46 to -0.25 ) intervention participants .
RESULTS	Conversely , the control group displayed no change in cardiorespiratory fitness while exhibiting increases in % FM ( 0.4 % ; 95 % CI , 0.1 to 0.7 ) , % CFM ( 0.6 ; 95 % CI , 0.1 to 1.1 ) , and VAT area ( 3.0 cm ( 2 ) ; 95 % CI , 1.6 to 4.4 ) .
RESULTS	Nonoverweight control participants increased in % FM ( 0.52 % ; 95 % CI , 0.13 to 0.91 ) , and their overweight and obese counterparts increased in VAT ( 4.76 cm ( 2 ) ; 95 % CI , 1.90 to 7.63 ) .
CONCLUSIONS	The physical activity intervention improved cardiorespiratory fitness , reduced % FM , and prevented accumulation of % CFM among prepubertal children with varying adiposity levels .
CONCLUSIONS	These findings provide support for daily physical activity recommendations to prevent excess fat mass accumulation in childhood .

