Objective This study aims to investigate the dynamic relationships between physical exercise (PE), body image (BI), and social anxiety (SA) among Chinese junior high school students, as well as to analyze the mechanism through which PE may alleviate SA by improving BI. Methods A total of 851 students (652 males, 391 females) from grades 7 and 8 across five secondary schools in Sichuan, Jiangsu, and Guangdong provinces were selected for this 12-month longitudinal study. Four waves of data were collected using validated questionnaires measuring PE, BI, and SA. The data were analyzed using a random intercept cross-lagged panel model (RI-CLPM). Results The study revealed the following findings: (1) PE showed significant positive correlations with BI at all four time points ( r = 0.308 to 0.463, p 0.001) and significant negative correlations with SA ( r = −0.142 to −0.301, p 0.001); (2) BI was also significantly negatively correlated with SA ( r = −0.138 to −0.313, p 0.001); (3) PE significantly reduced subsequent SA levels by improving BI. The total effect of the pathway PE(T1) → BI(T2) → SA(T3) was −0.301, with a mediation effect of −0.125 (accounting for 41.53% of the total effect). Conclusion This study elucidates the mediating mechanism through which PE alleviates SA by enhancing BI, providing scientific evidence for adolescent mental health interventions. Schools are advised to incorporate strategies in physical education curricula and activities that foster positive BI and social adaptation skills to promote psychological well-being.
Xing et al. (2026) studied this question.