Optimal Exercise Prescription for Cancer-Related Fatigue: A Dose-Response and Network Meta-Analysis of 166 Randomised Controlled Trials

Background: Cancer-related fatigue (CRF) significantly affects the quality of life in cancer population. Current guidelines do not provide a unified pharmacological treatment plan, highlighting the need for alternative therapies. While exercise has been suggested as potentially effective, the effective and optimal exercise dose remain unclear. This study aims to comprehensively assess the dose-response relationship between various exercise modalities and fatigue in cancer populations and to develop targeted exercise prescriptions. Methods: This systematic review and meta-analysis searched randomized controlled trials in PubMed, Web of Science, Embase, and the Cochrane Central Register of Controlled Trials, covering the period from database inception to July 16, 2025. Bayesian network and dose-response meta-analyses were conducted using a random-effects model to assess the impact of exercise on fatigue. Significance was indicated when the 95% credible interval (CrI) of the effect estimate excluded zero. Based on the meta-analysis results, we developed corresponding exercise prescriptions according to the effective and optimal dose range. The quality of evidence was evaluated using the Confidence in Network Meta-Analysis (CINeMA) web application. Findings: A total of 166 studies, involving 14,076 patients, were included in the systematic review. The findings revealed that aerobic exercise (0–180 minutes/week), resistance training (0–280 minutes/week), combined aerobic and resistance training (0–330 minutes/week), yoga (70–220 minutes/week), traditional Chinese exercise (120–300 minutes/week), and walking (0–110 minutes/week) were all significantly associated with reduced fatigue in cancer patients undergoing primary treatment. The relative ranking indicated that 220 minutes of yoga per week (SMD = 1.97, 95% CrI: 0.9, 3.04) may be the most effective exercise modality and dose for reducing CRF in this group. For cancer survivors who had completed primary treatments, aerobic exercise (0–160 minutes/week), combined aerobic and resistance training (0–200 minutes/week), yoga (0–330 minutes/week), and Pilates (100–150 minutes/week) were significantly associated with reduced fatigue. The relative ranking indicated that 110 minutes of Pilates per week (SMD = 2.05, 95% CrI: 0.07, 4.01) may be the most effective exercise modality and dose for alleviating fatigue in cancer survivors. Interpretation: The overall effect size, sample size, 95% CrI precision, and required exercise doses suggest that yoga may be the most suitable exercise modality for cancer population. Clinicians will use the evidence from this study to prescribe exercise regimens for managing CRF. However, the very low and low-quality evidence for several modalities emphasizes the need for more high-quality randomized controlled trials to validate the recommended doses and assess the safety of these interventions.