Bayesian network meta-analysis of exercise interventions for depression and anxiety in cancer survivors

BackgroundWe conducted a network meta-analysis to compare and rank exercise modalities for alleviating depression and anxiety in cancer survivors, estimate optimal doses, and provide prescribing guidance.MethodsWe synthesized randomized controlled trials published through July 2025 using an arm-based Bayesian multilevel network meta-analysis (NMA) with Hedges’ g and the surface under the cumulative ranking curve (SUCRA). We assessed risk of bias using Risk of Bias 2.0 (RoB 2.0) and evaluated certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.ResultsNinety-four RCTs (n = 7,668) were included. Versus non-exercise controls, exercise produced small-to-moderate improvements in depression and anxiety. For depression, Pilates (g = −0.35; 95% credible interval (CrI),−0.61 to −0.10; k = 3; SUCRA = 0.78), Tai Chi and Qi gong (g = −0.32; 95% CrI, −0.48 to −0.17; k = 11; SUCRA = 0.77), as well as aerobic exercise (g = −0.25; 95% CrI,−0.37 to −0.13; k = 24; SUCRA = 0.75) appeared to rank highly; favorable dose-response patterns were observed around approximately 2.8 metabolic equivalents (METs), 40 minutes per session, and six sessions per week. For anxiety, Pilates (g = −0.70; 95% CrI, −1.16 to −0.26; k = 1; SUCRA = 0.84) and high-intensity interval training (HIIT) (g = −0.36; 95% CrI,−0.66 to −0.05; k = 2; SUCRA = 0.79) were promising but based on few small RCTs, whereas Tai Chi and Qi gong (g = −0.35; 95% CrI,−0.51 to −0.19; k = 10; SUCRA = 0.69) and aerobic exercise (g = −0.27; 95% CrI,−0.40 to −0.15; k = 21; SUCRA = 0.62) showed stable benefits in larger samples. Dose-response suggested relatively favorable anxiety benefits with moderate intensity and duration at approximately five sessions per week. For both outcomes, effects plateaued around 20 weeks without additional gains at follow-up. Higher BMI and older age may attenuated effects; the female proportion showed no statistically significant association. Overall certainty tended to be low owing to risk of bias, small-study effects, and imprecision.ConclusionsMind-body exercises, especially Tai Chi and Qi gong, may be considered first because they were supported by a larger and more stable evidence base. Aerobic exercise also showed consistent benefits. Although Pilates and HIIT showed favorable estimated effects in some analyses, these findings should be interpreted cautiously because the certainty of evidence was low to very low. The recommended prescription for depression is approximately 2.8 METs, 40 minutes per session, six sessions per week; however, this estimate should be interpreted cautiously and individualized rather than applied as a fixed prescription. For anxiety, the recommended prescription is moderate-intensity, moderate-duration exercise five times weekly. Both treatment courses last approximately 20 weeks.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD420251110539, identifier CRD420251110539.