BACKGROUND: Life events are important risk factors for negative psychology such as depression and anxiety. However, individuals who experienced the same life events might not necessarily develop mental health problems. Some inherent psychological qualities among individuals may determine their mental health status under life events. Physical activity is beneficial to physical and mental health. What is the combined effect of physical activity and life events on individual depression and anxiety, and whether it can alleviate the psychological risk induced by life events, at present, there is no relevant research report. OBJECTIVE: To systematically analyze the combined effect of physical activity and life events on mental health of college students and the related mediating mechanism. METHODS: Guided by a series of hypotheses, the study conducted a cross-sectional survey on the physical activity level, life event experience, psychological vulnerability, depression and anxiety of 3552 Chinese college students. On the basis of hierarchical comparison, correlation analysis, logistics regression analysis and structural equation model method were further used to explore the effect of physical activity and life events on mental health and the relationship between variables, and to test the research hypotheses in sequence. RESULTS: Physical activity was negatively but life events were positively correlated with anxiety and depression
Psychological vulnerability played a partial mediating role between physical activity and life events and mental health, accounting for 22.17% and 23.42% of the total effect, respectively
Physical activity and life events had an interaction effect on mental health, and psychological vulnerability played a completely mediating role, accounting for 91.86% of the total effect
Physical activity could significantly reverse the negative effect of life events on mental health. CONCLUSIONS: Life events are important risk factors for poor mental health such as depression and anxiety. However, physical activity can effectively reverse the adverse effects of life events on mental health, and it is related to the mediating role of psychological vulnerability.