BACKGROUND: Little is known about children's leisure-time physical activity (PA) at school and how it is associated with contextual variables. The purpose of this study was to objectively assess children's voluntary PA during 3 daily periods and examine modifiable contextual factors.
METHODS: We conducted SOPLAY (System for Observing Play and Leisure Activity in Youth) observations before school, during recess, and at lunchtime in 137 targeted activity areas in 13 elementary schools over 18 months. During observations, each child was coded as Sedentary, Walking, or Vigorous, and simultaneous entries were made for area characteristics (accessibility, usability, presence of supervision, loose equipment, and organized activities). Logistic regression analysis was used to test associations between PA and area characteristics.
RESULTS: Assessors made 2349 area visits and observed 36,995 children. Boys had more moderate-to-vigorous physical activity (MVPA; 66.2 vs 60.0%, p < .001) and more vigorous PA (29.8 vs 24.6%; p < .001) than girls. Areas were typically accessible and usable, but provided organized activities infrequently (16.5%). Odds of engaging in MVPA were greater during lunch and recess than before school and in areas with play equipment (p < .05).
CONCLUSIONS: Children accrued a substantial amount of voluntary PA during leisure time at school. Their PA would likely be increased if school playground equipment was more readily available and if supervisors were taught to provide active games and promote PA rather than suppress it.