Abstract
BACKGROUND: Across countries, young people are not sufficiently physically active. The evidence confirms that beyond demographic and individual agents, individuals participate within their social and physical environment. The ecological model enables a search for the modifiable factors in specific populations, as it allows consideration of factors affecting individuals' lives on different levels, as well as considering the interplay of those factors. The aim of this study was to examine the complex interconnections among environmental, social capital and motivational factors at different levels, within an ecological model for high school students' moderate-to-vigorous physical activity during their leisure time. METHODS: This cross-sectional population-based study included 1285 students from 14 to 18 years old, with a mean age of 16.14 ± 1.22. Physical activity, neighborhood physical activity recourses, neighborhood safety, social capital, physical activity motivation and sociodemographic factors were evaluated. Logistic regression, mediation and moderation analyses were performed predicting moderate-to-vigorous physical activity during leisure time. RESULTS: In the final multivariate logistic regression model, greater social participation (OR 1.03 [1.01-1.05]), higher relative autonomy index (OR 1.11 [1.06-1.15]) and male gender (OR 1.71 [1.13-2.57]) directly predicted meeting MVPA recommendations. Any significant moderation effects (p > 0.05) of environmental characteristics were not found for the relationship between social capital, motivational factors and moderate-to-vigorous physical activity. The evidence of positive indirect mediation effects was found in all five models for social capital components as all CIs for its βs do not contain 0, though standardized effect sizes were between 0.02 and 0.07, indicating small effect sizes. CONCLUSION: These findings provide support for the presence of some direct and indirect pathways from social capital to moderate-to-vigorous physical activity. Future intervention strategies should focus on strengthening physical activity motivation by encouraging the development of social network and social participation as well as family, neighborhood and school social capital within the framework of the ecological model.