Association between physical activity and depression in university students: a systematic review and meta-analysis with public health implications

Objective To systematically review and meta-analyze the association between physical activity and depression among university students, quantify the linear correlation between physical activity level and depressive symptoms, and examine the binary association of insufficient physical activity or sedentary behavior with depression risk, thereby providing evidence-based support for mental health promotion and public health interventions in higher education settings. Methods Following PRISMA guidelines, we systematically searched PubMed, Web of Science, Embase, Scopus, and PsycINFO from inception to March 31, 2026, for observational studies examining the relationship between physical activity and depression in university students. Two reviewers independently performed study selection, data extraction, and quality assessment. For studies reporting correlation coefficients, separate meta-analyses were conducted for Pearson and Spearman correlations using Fisher’s z-transformation under a random-effects model. For studies reporting binary outcomes, adjusted odds ratios (ORs) with 95% confidence intervals were extracted and pooled separately for physical activity and sedentary behavior groups. Results A total of 36 studies were included: 30 in the linear correlation meta-analysis and 6 in the binary association meta-analysis. The linear correlation analysis comprised 31 effect sizes with a total sample of 30,307 individuals. The pooled correlation estimates showed an inverse direction but substantial to extreme heterogeneity (Pearson: r = −0.19, 95% CI: −0.28 to −0.11, I 2 = 94.4%; Spearman: r = −0.44, 95% CI: −0.73 to −0.01, I 2 = 99.2%), indicating that these pooled estimates should be interpreted as average directional trends rather than precise or universally applicable effect sizes. After trim-and-fill correction, the Pearson correlation remained statistically significant (r = −0.114, 95% CI: −0.209 to −0.016). The binary association analysis showed that the pooled OR for the physical activity group (4 studies) was 0.53 (95% CI: 0.27 to 1.07), suggesting a protective trend of higher physical activity against depression that did not reach statistical significance; the pooled OR for the sedentary behavior group (2 studies) was 1.60 (95% CI: 1.26 to 2.04), indicating a significant association between higher sedentary behavior and increased depression risk. Subgroup analyses revealed a stronger negative association between physical activity and depression during and after the COVID-19 period. Conclusion Physical activity promotion and sedentary behavior reduction may be practical components of campus mental health strategies, including brief activity breaks during long lectures, low-threshold exercise opportunities, and active commuting support. However, because most included studies were cross-sectional, geographically skewed toward Chinese samples, and highly heterogeneous, these implications should be interpreted cautiously as public health directions rather than causal or universally generalizable recommendations.