Independent, Joint-aerobic, And Dose-response Associations Of Resistance Exercise With Cancer Mortality: A Living Meta-analysis

PURPOSE: To determine: 1) if resistance exercise (RE) is associated with lower cancer mortality risk independent of, and jointly with, aerobic exercise (AE); and 2) whether there is a dose-response pattern of cancer mortality by amount of RE. METHODS: We searched MEDLINE, Embase, SPORTDiscus, The Cochrane Library, and SCOPUS from inception to February 13, 2024. We included prospective cohort studies in which: 1) AE and RE were the exposures and cancer mortality the outcome; and 2) nonclinical adult populations (aged ≥18 years) were sampled. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer mortality were pooled using random effects meta-analysis models. The independent effect of RE from AE was based on models with AE as a covariate. A random effects dose-response meta-analysis characterized the association between the RE dose (sessions/week) and cancer mortality risk. RESULTS: Eight cohort studies from 5 countries (Mean follow-up time = 12.1 years) were included (8, 6, and 5 examined independent, joint, and dose-response associations, respectively). Relative to no RE, meeting the WHO guideline for RE (1-2 sessions/week), independent of meeting the AE guideline (≥150 minutes/week at moderate to vigorous intensities), was associated with a lower risk of cancer mortality (HR: 0.95, 95% CI: 0.85-0.97). Compared to meeting neither guideline, meeting the joint AE-RE guideline was associated with a larger difference in cancer mortality risk (HR: 0.71, 95% CI: 0.63-0.80). The dose-response meta-analysis showed evidence of a non-linear, U-shaped relationship between the amount of RE (independent of AE) and cancer mortality risk. In detail, relative to no RE, participating in 1-2 sessions/week of RE was associated with a lower risk of cancer mortality (HR: 0.90; 95% CI: 0.83-0.97), but there was no difference in cancer mortality risk between those who exceeded the guideline and those who participated in no RE (HR: 1.09, 95% CI: 0.89, 1.19). CONCLUSIONS: With the increasing global prevalence of obesity and physical inactivity, RE—a more movement-varied, lower-impact exercise modality—should receive more attention in public health policy to help alleviate the global burden of cancer mortality. Public health surveillance instruments capturing RE volume are needed to improve prescription. This work was supported by grant number 2T32HL007779-29 from the US National Heart, Lung, and Blood Institute.