Factors associated with out-of-school physical activity among Chinese children and adolescents: A stratified cross-sectional study

This observational study examined the factors associated with the physical activity (PA) of children and adolescents outside of school within the framework of Problem Behavior Theory (PBT). This cross-sectional study obtained data from 6528 children and adolescents aged 6–16 years recruited from ten schools in Shanghai, China. The questionnaire measured out-of-school PA and PBT-based correlates. A series of multiple linear regressions were used to explore the factors influencing children and adolescents' out-of-school PA separately. Structural equation modeling (SEM) was used to explore the association between the three systems of PBT and out-of-school PA. Higher intrinsic motivation is positively associated with increased PA for children (b = 1.038, 95%CI: 0.897–1.180) and adolescents (b = 1.207, 95%CI: 0.890–1.524). Greater frequency of parental involvement in PA correlates with elevated PA for both children (b = 2.859, 95%CI: 2.147–3.572) and adolescents (b = 2.147, 95%CI: 0.311–3.983). In children, increased use of community exercise areas or facilities (b = 1.705, 95%CI: 0.234–3.176) and higher recreational screen time (b = 9.732, 95%CI: 5.614–13.850) are associated with higher PA. The SEM showed that factors of the personality system had a significant direct effect on out-of-school PA among children and adolescents, and factors of the behavior system also had a significant effect on children. Our findings suggest that the personality system, particularly intrinsic motivation, is important in promoting out-of-school PA in children and adolescents. For children, modifiable health behaviors in the behavior system can similarly influence PA. •31.6% of children and adolescents were inactive outside of school.•Intrinsic motivation is positively associated with out-of-school physical activity.•Parental accompanying exercise positively relates to out-of-school physical activity.•Attention also should be paid to environmental and health-behavioral impacts.