Association between cardiorespiratory fitness and depressive symptoms in children and adolescents: a systematic review and meta-analysis

Background: Higher cardiorespiratory fitness (CRF) is associated with lower depressive symptoms in adults. However, no systematic review with meta-analysis assessed the cross-sectional associations between CRF and depressive symptoms in children and adolescents. Therefore, this meta-analysis assessed the relationship between CRF and depressive symptom in these populations. Methods: Cross-sectional data evaluating the correlation between CRF and depression were searched, from database inception through 21/05/2020, on PubMed, PsycINFO, Web of Science, and SPORTDiscus. Age, sex, CRF and depression assessments, and correlations were extracted. A random-effects meta-analysis was conducted, and the potential sources of heterogeneity were also explored through meta-regression analysis. Results: Across 14 effects of 11 unique studies, including a total of 7,095 participants (median age=12.49) with nearly equal sex distribution (median=53% females), it was found that higher CRF was associated with lower depressive symptoms in children and adolescents (r =-0.174, 95%CI -0.221 to -0.126, p<0.001, I2=75.09, Q value=52.19). No moderators were identified. Conclusion: Available evidence supports the notion that higher CRF is inversely associated with depressive symptoms in children and adolescents. Physical activity and exercise interventions targeting improving CRF should be promoted for these populations. Further studies, including clinical populations, should be conducted to assess objective measures of aerobic fitness and body composition, while controlling for puberty status, to better characterize this association.