Effect of supervised exercise on aerobic capacity in cancer survivors: Adherence and workload predict variance in effect

AIM: To examine the efficacy of supervised aerobic exercise training on aerobic capacity in survivors of cancer.METHODS: We conducted a systematic search identifying randomized controlled trials of supervised aerobic exercise interventions among adult cancer survivors with aerobic capacity(VO2max/peak) as the primary outcome. We calculated pooled effect sizes and performed multiple regression moderator analysis. RESULTS: We identified 18 studies including 1149 survivors of cancer. Studies included mixed cancer groups(4 studies), breast cancer(10 studies), hematological cancers(2 studies), lung cancer(1 study) and liver cancer(1 study). Survivors of cancer who participated in supervised aerobic exercise training improved aerobic capacity(VO2peak) more than controls(18 comparisons, 1093 participants; standardized mean effect: 0.74; 95%CI: 0.52, 0.96; P < 0.001). However, there was significant heterogeneity among the included trials(I2: 63%; P < 0.001). Sixty-six percent of the between-study heterogeneity was explained by differences in exercise adherence and total exercise workload among studies(R2: 65.8%; P < 0.04). CONCLUSION: Supervised aerobic exercise training provides a moderate-to-large beneficial effect on aerobic capacity among survivors of cancer. Aerobic capacity was improved to a greater degree in exercise studies with better participant attendance and higher overall exercise workload.