School opportunities and physical activity frequency in nine year old children

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. 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 a parts per thousand yen 4 of the following opportunities: PE class a parts per thousand yen 2 times/week, extracurricular sports animator, gymnasium, swimming pool, schoolyard equipped for games, and a parts per thousand yen 1 outdoor sports playing fields. Multilevel modelling techniques were used to investigate the association between school-level PA opportunity and student-level PA frequency. No main effect of 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. 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.