Twenty-two adolescents were divided into 4-week ( n = 6 , weight 48.114.9 kg , body fat 27.48.4 % ) and 8-week exercise groups ( n = 6 , weight 43.410.9 kg , body fat 28.512.8 % ) , that performed supervised , play-based physical activity , versus an age-matched 8 week control group that maintained their typical summer break ( n = 10 , weight 41.710.0 kg , body fat 23.78.0 % ) .