School opportunities and physical activity frequency in nine year old children

Objective: To examine the association between physical activity (PA) opportunities at school and participation in PA outside of school physical education (PE) classes among 9 year old children. Methods: Data were obtained in a representative sample of 1 267 students nested within 69 schools who completed questionnaires; principals provided data on schools. Students' PA frequency was defined as all reported episodes of past week PA, excluding PE class. Schools were categorized as "high-opportunity" if they provided ≥ 4 of the following opportunities: PE class ≥ 2 times/week, extracurricular sports animator, gymnasium, swimming pool, schoolyard equipped for games, and ≥1 outdoor sports playing fields. Multilevel modelling techniques were used to investigate the association between school-level PA opportunity and student-level PA frequency. Results: No main effectof school-level PA opportunities on PA frequency was observed. However, overweight boys attending high-opportunity schools were significantly more active than those attending low-opportunity schools. Conclusions: The association between PA frequency and school-level PA opportunity differs by sex and weight status. Overweight boys in particular may benefit from health promotion strategies providing greater opportunities for school PA.