The relationship between physical activity, working memory, and mathematics achievement on the basis of socioeconomic status: the mediating role of physical fitness level

Background Socioeconomic disparities influence both academic achievement and health-related behaviors during adolescence; however, the mechanisms linking physical activity, physical fitness, and cognitive functions—particularly working memory—to academic outcomes remain insufficiently understood. Therefore, this study investigated the relationships among socioeconomic status (SES), physical activity, physical fitness, working memory, and mathematics achievement in adolescents, with a specific focus on the mediating role of physical fitness. Methods A cross-sectional study was conducted with 310 ninth-grade students from five secondary schools in Türkiye. SES was assessed using a composite index including parental education, occupation, income, and household characteristics. Physical activity, physical fitness, working memory, and mathematics achievement were evaluated using validated standardized measures. Structural equation modeling (SEM) was applied to examine direct associations and the mediating role of physical fitness. Results Maternal and paternal education levels were positively associated with mathematics achievement, whereas only maternal education showed a significant association with physical activity. SES was not directly associated with either physical activity or mathematics achievement. Working memory significantly predicted mathematics achievement. Physical activity was positively associated with physical fitness, which in turn predicted working memory. Additionally, physical fitness partially mediated the relationship between physical activity and working memory. Conclusion Although causal relationships cannot be inferred due to the cross-sectional design, the findings suggest that regular engagement in physical activity and the development of physical fitness may contribute to improved cognitive functioning and academic performance during adolescence. Interventions aimed at enhancing physical fitness and promoting equitable access to physical activity opportunities may support both cognitive and educational outcomes.