Internet-based exercise interventions for the treatment of depression and anxiety: a systematic review and meta-analysis of randomised controlled trials

Background Depression and anxiety frequently co-occur and impose substantial public health burdens. Although established treatments are effective, barriers to access and engagement remain. Internet-based exercise may offer a scalable complement to existing treatment options. This review evaluated its effects on depressive and anxiety symptoms. Methods This systematic review and meta-analysis was reported in accordance with PRISMA 2020 and registered in PROSPERO (CRD420251131843). We included randomised controlled trials (RCTs) of Internet-delivered structured exercise compared with non-exercise controls and reporting validated measures of depression and/or anxiety. PubMed, Embase, Web of Science, and EBSCOhost were searched, supplemented by manual searches. Risk of bias was assessed using RoB 2. Random-effects meta-analysis was used to calculate standardised mean differences (SMDs) with 95% confidence intervals (CIs). Results Thirteen RCTs were included. Eleven trials comprising 1,066 participants contributed to the depressive symptom meta-analysis, and seven trials comprising 607 participants contributed to the anxiety symptom meta-analysis. Internet-based exercise was associated with statistically significant reductions in depressive symptoms (SMD = − 0.53, 95% CI − 0.80 to − 0.26; I² = 77.2%) and anxiety symptoms (SMD = − 0.41, 95% CI − 0.65 to − 0.17; I² = 48.9%). Most trials were rated as having some concerns regarding risk of bias (11/13), primarily related to outcome measurement. The certainty of evidence was low for depressive symptoms and moderate for anxiety symptoms. Conclusion Internet-based exercise may reduce depressive and anxiety symptoms and may serve as a scalable nonpharmacological complement to existing treatments. However, the findings should be interpreted cautiously because of substantial heterogeneity in depressive outcomes and limitations in the certainty of evidence. Further high-quality trials are needed to clarify long-term effects and implementation considerations. Registration PROSPERO CRD420251131843. Clinical trial number Not applicable.