Modalities and dosage of exercise interventions for improving adolescent mental health: a systematic review and meta-analysis

Objective This study aims to: (1) update existing evidence on exercise interventions improving adolescent mental health; (2) exploring potentially effective models and dosages of exercise interventions to improve adolescents’ mental health; (3) provide evidence-based medical insights to inform future research and non-clinical treatments for mental disorders. Methods We searched six databases—Web of Science, PubMed, Embase, The Cochrane Library, SportDiscus, and Scopus—for randomized controlled trials (RCTs) on exercise interventions for adolescent mental health published since the databases were established. We used the Rob 2.0 risk of bias tool to assess the methodological quality of the included studies, and then performed conventional meta-analyses, network meta-analyses, subgroup analyses, and sensitivity analyses using R software. Results A total of 17 randomized controlled trials were included. The meta-analysis results showed that, compared with the control group, exercise intervention had a significant positive effect on improving adolescents’ depression (g = −0.34, p = 0.0109), anxiety (g = −0.45, p < 0.0001), and stress (g = −0.49, p < 0.0001). Subgroup analysis and sensitivity analysis results indicate that the high heterogeneity among groups is likely due to an imbalance in the number of studies and sample sizes across subgroups. Based on the results of a network meta-analysis and SUCRA probability ranking, adolescents may derive potential benefits from low-intensity TCC exercises performed less than three times per week, with each session lasting more than 60 min; anxiety symptoms may benefit from moderate-to-high-intensity HIIT sessions lasting more than 60 min per session, performed fewer than three times per week; and low-intensity yoga sessions lasting 30–60 min per session, performed fewer than three times per week, may help alleviate stress symptoms in adolescents. Due to the limited number of studies included, the Egger’s test was not statistically significant, and publication bias cannot be ruled out; therefore, the results should be interpreted with caution. Conclusion Exercise intervention, as an alternative non-pharmacological treatment approach, plays a positive role in improving adolescents’ mental health. The exercise regimens and dosages recommended in this study are based on a synthesis of the existing evidence; further research is needed to explore the effects of interventions involving different variables. Systematic review registration The study has been registered with the International Prospective Systematic Reviews Register (PROSPERO) (CRD420251087193).