Background: Afterschool programs (ASPs) can provide opportunities for children to accumulate moderate-to-vigorous physical activity (MVPA). The optimal amount of time ASPs should allocate for physical activity (PA) on a daily basis to ensure children achieve policy-stated PA recommendations remains unknown.
Methods: Children (n = 1248, 5 to 12 years) attending 20 ASPs wore accelerometers up to 4 nonconsecutive week days for the duration of the ASPs during spring 2013 (February-April). Daily schedules were obtained from each ASP.
Results: Across 20 ASPs, 3 programs allocated ≤ 30min, 5 approximately 45 min, 4 60 min, 4 75 min, and 4 ≥ 105 min for PA opportunities daily (min·d-1). Children accumulated the highest levels of MVPA in ASPs that allocated ≥ 60 min·d-1 for PA opportunities (24.8-25.1 min·d-1 for boys and 17.1-19.4 min·d-1 for girls) versus ASPs allocating ≤ 45 min·d-1 for PA opportunities (19.7 min·d-1 and 15.6 min·d-1 for boys and girls, respectively). There were no differences in the amount of MVPA accumulated by children among ASPs that allocated 60 min·d-1 (24.8 min·d-1 for boys and 17.1 min·d-1 for girls), 75 min·d-1 (25.1 min·d-1 for boys and 19.4 min·d-1 for girls) or ≥ 105 min·d-1 (23.8 min·d-1 for boys and 17.8 min·d-1 for girls). Across ASPs, 26% of children (31% for boys and 14% for girls) met the recommended 30 minutes of MVPA.
Conclusions: Allocating more than 1 hour of PA opportunities is not associated with an increase in MVPA during ASPs. Allocating 60 min·d-1, in conjunction with enhancing PA opportunities, can potentially serve to maximize children's accumulation of MVPA during ASPs.