Physical Activity and Adolescent Mental Health in China: The Mediating Role of Social Capital

Background: Adolescent mental health is critical for healthy development, yet mental health issues remain prevalent globally. Physical activity (PA) has been linked to mental health benefits, but evidence among adolescents is inconsistent, and mechanisms remain underexplored. Methods: We analyzed cross-sectional observational data drawn from the 2014 wave of the China Education Panel Survey (CEPS), which surveyed 9920 students in total. After excluding cases with missing values on any focal variable, 7995 Chinese middle school students were retained for analysis to examine the association between PA and mental health and, in particular, the mediating role of social capital (as captured by social networks, adherence to collective norms, and trust). We employed regression and mediation analyses. Results: We found that greater PA was positively associated with better mental health, operationalized as reduced affective–symptomatic symptoms. This relationship was mediated by two dimensions of social capital—social networks and adherence to collective norms—while trust did not serve as a significant mediator. Conclusions: These findings suggest that PA may enhance adolescent mental health by fostering social connections and group engagement. Promoting PA and supportive social environments in school settings could contribute to improved mental well-being among adolescents.