Optimal Exercise Dose for Improving Multidimensional Health Outcomes in Colorectal Cancer Patients: A Systematic Review, Meta-Analysis and Meta-Regression.
Verbatim Formal Study Abstract
This study aimed to investigate the dose-response relationships between exercise prescription parameters and a range of health outcomes in patients with colorectal cancer (CRC). The following PRISMA guidelines, a systematic search of five databases was conducted. The inclusion criteria were randomized controlled trials (RCTs) of exercise interventions lasting ≥ 4 weeks in patients with CRC. Robust Variance Estimation (RVE) was used to synthesize the overall effects of exercise interventions across six outcome domains, including cardiorespiratory fitness (CRF) and muscular fitness (MF). Univariable RVE regression models and MetaForest analyses were employed to examine the moderating effects of two groups of variables: exercise prescription moderators and patient background characteristics. Risk of bias was assessed using the Cochrane tool, and the quality of evidence was evaluated using the GRADE approach. A total of 26 RCTs, involving 1731 CRC patients and 266 effect sizes, were included. CRF (ES = 0.35, p < 0.01) and MF (ES = 0.45, p < 0.01) showed statistically significant improvements. Regression analyses revealed threshold effects for both CRF and MF, with maximal improvements requiring sustained engagement in moderate-to-high intensity exercise. Subgroup analyses indicated that prehabilitation interventions were the most effective, while interventions during active treatment exhibited a decline-rebound trend over time. Based on these findings, high-frequency and moderate-to-high volume interventions with individualized load regulation are recommended during the pre-treatment phase. During active treatment, a more cautious approach is advised, involving reduced exercise volume during peak symptom periods and gradual progression during recovery.