Optimal intensity and dose of exercise to improve university students' mental health: a systematic review and network meta-analysis of 48 randomized controlled trials.

Background: A systematic evaluation and network meta-analysis (NMA) using randomized controlled trials (RCTs) was conducted to investigate the effects of different exercise intensities and dosages on the mental health of college students.

Methods: A systematic search of eight electronic databases of RCTs involving mental health exercise interventions for college students was conducted, which included data from the inception of the databases through July 2024. Two independent reviewers assessed the quality of the literature. Pairwise, network, and dose‒response meta-analyses were conducted via random-effects models to analyze the effects of exercise on college students' mental health.

Results: A total of 48 RCTs (3951 patients) were included. Light, moderate, and vigorous exercise were all significantly effective at reducing symptoms of depression, anxiety and stress, whereas very light exercise was only effective at reducing symptoms of depression and stress. Surface under the cumulative ranking curve (SUCRA) probability ranking revealed that vigorous exercise had the highest probability of being the best intervention intensity to improve depression and stress symptoms, and the best exercise intensity to improve anxiety symptoms was moderate. The minimum threshold for overall exercise intervention for depressive symptoms was 150 METs-min per week, the benefits provided after doses above 1300 METs-min per week were less pronounced, and the predicted maximum significant response dose was 860 METs-min per week, which was the same as the predicted data for moderate exercise.

Conclusion: Very light, light, moderate, and vigorous exercise are all potentially effective exercise intensities for improving the mental health of college students, with no significant difference in effectiveness across the four exercise intensities. SUCRA rankings revealed that vigorous exercise is the most effective intervention for depression and stress and that moderate exercise is the most effective intervention for anxiety. Exercise interventions for depressive symptoms have a low dosage threshold, are simple and easy to administer, and are good treatments for psychological problems in college students.