Randomized , parallel-group clinical trial at community-based exercise facilities in Ottawa ( Ontario ) and Gatineau ( Quebec ) , Canada , among previously inactive postpubertal adolescents aged 14 to 18 years ( Tanner stage IV or V ) with body mass index at or above the 95th percentile for age and sex or at or above the 85th percentile plus an additional diabetes mellitus or cardiovascular risk factor .