Sociodemographic Factors and Adolescent Physical Activity: The Mediating Role of Physical Activity-Related Health Competence

BACKGROUND: Adolescents' physical activity (PA) is often below health-promoting levels and shows social gradients. Physical activity-related health competence (PAHCO) has been proposed as a mechanism linking social conditions to health-relevant PA. We examined whether PAHCO facets mediate associations between sociodemographic factors and adolescents' PA. METHODS: We pooled 2 cohorts of German students (N = 1247, mean age = 12.6 [1.9]y). Physical activity was assessed with 2 items on days with ≥60 minutes per day of moderate-to-vigorous PA. Physical activity-related health competence was operationalized as PA mood regulation, PA self-control, and assumption of responsibility for one's health. Predictors were sex, age, books at home (socioeconomic status proxy), language other than German spoken at home (migration proxy), and sport-club membership; study wave was controlled. Theory-driven path models estimated indirect, direct, and total effects. RESULTS: All PAHCO facets showed positive unique associations with PA (β = 0.11-0.22). Sport-club membership had the strongest total association with PA (β = 0.55), 41% of which was mediated by PAHCO. Books at home showed a smaller positive total association (β = 0.13, 22% mediated), and age a small negative association (β = -0.06, 24% mediated). Language at home showed a small positive indirect association via PAHCO but no total effect; sex showed no total effect. CONCLUSIONS: Physical activity-related health competence facets partially account for social and contextual gradients in adolescents' PA, suggesting PAHCO as an equity-relevant midstream pathway. Targeting PAHCO facets in physical education, extracurricular and community programs may help adolescents translate opportunities into health-enhancing PA.