Abstract
BACKGROUND: Physical exercise is crucial for the physical and mental health of college students, yet improving their exercise adherence remains a pressing challenge. Based on Self-Determination Theory (SDT), physical education (PE) teacher support may enhance students' self-determined motivation by satisfying their basic psychological needs, thereby promoting exercise adherence. However, the dynamic relationships among teacher support, self-determined motivation, and exercise adherence have not been fully explored. OBJECTIVE: This study aimed to investigate the dynamic impact of PE teacher support on college students' exercise adherence and to verify the mediating role of self-determined motivation. METHODS: A longitudinal design was adopted, with three waves of data collection (T1, T2, T3) from 555 college students. Cross-lagged models and longitudinal mediation models were constructed to analyze the dynamic relationships among variables. RESULTS: This study found that T1 teacher support significantly and positively predicted T2 self-determined motivation (β = 0.187, p < 0.001) and T2 exercise adherence (β = 0.379, p < 0.001). Self-determined motivation mediated the relationship between teacher support and exercise adherence (mediation effect = 0.039, 95% CI = [0.007, 0.072]). Additionally, bidirectional predictive relationships existed between self-determined motivation and exercise adherence, although the bidirectional relationship between teacher support and exercise adherence was inconsistent across time points. CONCLUSION: PE teacher support exerts a significant longitudinal impact on college students' exercise adherence, primarily through direct effects and the mediating role of self-determined motivation. These findings provide theoretical support for college physical education practices, emphasizing the critical role of teacher support in fulfilling students' basic psychological needs and enhancing exercise adherence. Future research should expand sample sizes and extend tracking periods to comprehensively reveal the dynamic mechanisms among variables.