The effect of physical activity on depression in university students: the mediating role of self-esteem and positive psychological capital

Objective This study aimed to investigate the relationship between physical exercise and depression among college students, focusing on the mediating role of self-esteem and positive psychological capital. Methods Group psychological measurements were conducted on 579 students using various scales, including the Physical Activity Rating Scale (PARS-3), Self-Esteem Scale (SES), Positive Psychological Capital Questionnaire (PPQ), and Self-rating Depression Scale (SDS). The data was analyzed using SPSS 26.0 and bootstrap methods to test and analyze the effects. Results A negative correlation between physical exercise and depressive mood, with physical exercise significantly predicting college students' depressive mood. Additionally, physical exercise was found to positively predict self-esteem and positive psychological capital, both of which are negatively predictive of depressive mood. Self-esteem and positive psychological capital were identified as significant mediators between physical exercise and depressive mood, with three mediating paths: physical exercise, self-esteem, and depressed mood (Path 1), exhibited an indirect effect of 0.017, with the bootstrap 95% confidence interval excluding 0 (LLCI = −0.051, ULCI = −0.004) and accounting for 8.30% of the total effect. Physical exercise, positive psychological capital, and depression emotion (Path 2), had an indirect effect of 0.049, with the bootstrap 95% confidence interval also not containing 0 (LLCI = −0.088, ULCI = −0.011) and contributing to 23.90% of the total effect. Physical exercise, self-esteem, positive psychological capital, depressed mood (Path 3), demonstrated an indirect effect of 0.006, with the bootstrap 95% confidence interval excluding 0 (LLCI = −0.011, ULCI = −0.001) and representing 2.90% of the total effect. Conclusion Physical exercise negatively predicts depressive mood among college students and has a mediating effect through self-esteem and positive psychological capital, creating a chain-like impact on their depressive symptoms.