Meta-analysis of 21 RCTs shows structured exercise cuts cancer mortality by 23%

The British Journal of Sports Medicine synthesis aggregated randomized controlled trials through 2025, with breast cancer dominating the sample. Participants assigned to supervised programs showed consistent survival gains strongest in early-stage disease and among those completing at least 70% of sessions. No clear benefit emerged for time-to-progression or pathologic complete response.

Exercise effects likely operate through improved tumor perfusion, immune mobilization, reduced sex hormones, and lower circulating glucose, mechanisms supported by prior physiologic studies in NEJM and JAMA Oncology. These pathways align with observational data showing dose-dependent survival gradients in colorectal and prostate cohorts, yet the current evidence remains limited by migration to healthier behaviors in controls and sparse data beyond breast cancer.

Incorporating routine aerobic exercise into adjuvant care therefore offers a low-cost intervention with measurable survival impact. Future trials must test scalable delivery models in advanced disease and non-breast populations while tracking adherence thresholds that maximize benefit.

Larger, multi-center RCTs with objective activity monitoring are required to confirm durability beyond five years and to establish optimal intensity prescriptions.