RESUMEN
Objective: Many Chinese teenagers are experiencing high mental stress levels due to epidemic-related restrictions and closures. Mental stress can induce numerous associated symptoms, and physical exercise is considered to buffer mental stress. However, it remains unclear whether health motivation regulates the relationships among mental stress, physical exercise, and stress symptoms. This study examined whether mental stress events during the epidemic can predict stress symptoms, whether physical exercise can buffer mental stress, and whether the mental stress buffer effect is enhanced when health motivation regarding physical exercise is high. Methods: In total, 2,420 junior high school students (1,190 boys and 1,230 girls; 826 seventh-grade students, 913 eighth-grade students, and 681 ninth-grade students) from nine provinces nationwide were selected to investigate mental stress events, symptoms, health motivation, and physical exercise in adolescents. The hypothesis was tested with a multiple regression analysis. Results: A positive relationship between adolescent mental stress events and stress symptoms was observed, and an interactive relationship was found among health motivation, physical exercise, and mental stress factors. Specifically, the mental stress-buffering effect of physical exercise was significant only when health motivation was high. Conclusion: In the post-epidemic period, the influence of mental stress events on stress symptoms in adolescents was found to be buffered by physical exercise only in terms of high health motivation. This result highlighted the role of health motivation in the buffering effect of physical exercise on mental stress during an epidemic.