Psychosocial factors associated with physical activity and sedentary behavior in adolescents: evidence from physical education contexts in Quito

Physical Education (PE), as a psychoeducational context, plays a central role in understanding adolescents' engagement in physical activity and sedentary behavior. This study aimed to examine the associations between psychosocial variables related to the PE experience and levels of physical activity both within PE and during leisure time, as well as recreational screen time among adolescents in Quito, Ecuador. A cross-sectional sequential explanatory mixed-methods design was employed, integrating quantitative and qualitative evidence. The quantitative sample included 5,515 students aged 12-18 years from 11 public, publicly funded private, and private schools in urban and rural areas. The qualitative component consisted of six student focus groups and one teacher focus group. Measures included physical activity, screen time, motivational orientation, situational intrinsic motivation in PE, self-esteem, motor self-efficacy, and perceived autonomy support. Analyses comprised descriptive statistics, sex-based comparisons, and Spearman correlations, complemented by thematic analysis of qualitative data. Results indicated that 29% of adolescents did not comply with the 2-h daily threshold for recreational screen time (95% CI: 27.80-30.20), with non-compliance increasing with age and being more prevalent among girls than boys. Bivariate associations revealed a small positive relationship between self-efficacy and leisure-time physical activity (rho = 0.050), whereas situational intrinsic motivation in PE showed a small negative association. Qualitative findings confirmed and extended these patterns, highlighting that screen time competes with academic demands and leisure, and that perceived competence and pedagogical climate are key factors shaping motivation and participation. Overall, the findings underscore the relevance of psychosocial factors within PE, while emphasizing the role of contextual and structural conditions in shaping adolescents' physical activity and sedentary behavior. These results support the need for gender-sensitive and context-responsive school-based interventions to promote active lifestyles.