Structure of Physical Activity Opportunities Contribution to Children's Physical Activity Levels in After-School Programs.

Background: The primary purpose of this study was to determine which physical activity (PA) opportunity elicits the most moderate to vigorous PA (MVPA) in after-school programs. This study used a 3-group cross-over design in which participants were exposed to 3 variations of activity structures: free play, organized, or a mixture.
Methods: PA was measured using ActiGraph GT3X+ accelerometers. All data were transformed into percentage of time spent sedentary or in MVPA. Repeated-measures mixed-effects models were used to examine differences in MVPA and sedentary among the 3 activity sessions. Participants included 197 unique children, aged 5-12 years, and were 53% male and 55% white.
Results: Statistically significant differences were observed in the percentage of time boys spent in MVPA during free play and mixed compared with organized only sessions (35.8% and 34.8% vs 29.4%). No significant difference was observed in the percentage of time girls spent in MVPA during free play compared with organized or mixed (27.2% and 26.1% vs 26.1%). Both boys and girls experienced ∼10% less time sedentary during free play compared with the others.
Conclusion: Offering free play during PA opportunities can help children attain as much if not more MVPA compared with only offering organized, adult-led games.