Resistance exercise interventions during and following cancer treatment: a systematic review

Findings from prior systematic reviews suggest that exercise results in meaningful improvements in many clinically relevant physiologic and quality of life (QOL) outcomes during and following cancer treatment. However, the majority of exercise-cancer studies have focused upon the benefits of aerobic exercise (AE) and knowledge of the efficacy of resistance exercise (RE) alone as a supportive care intervention for cancer patients and survivors remains limited. Consequently, the purpose of this review was to provide the first systematic evaluation of the effects of RE alone upon clinically relevant physiologic and QOL outcomes during and following cancer treatment. Literature searches were conducted to identify studies examining RE interventions in cancer patients and survivors. Data were extracted on physiologic (fitness, physical function, and body composition) and QOL (fatigue, psychological well-being, and cancer-specific and global QOL outcomes. Cohen's d effect sizes were calculated for each outcome. A total of 15 studies (6 in samples undergoing active cancer treatment and 9 in samples having completed cancer treatment) involving 1,077 participants met the inclusion criteria. Findings revealed that, on average, RE resulted in large effect-size improvements in muscular strength (d = 0.86), moderate effect-size improvements in physical function (d = 0.66), and small effect-size improvements in body composition (d = 0.28) and QOL (d = 0.25) outcomes. The effect sizes observed following RE are comparable in magnitude to the effects of exercise interventions reported in prior comprehensive reviews of the exercise-cancer literature which primarily focused upon AE. Additionally, the methodologic quality of the studies was generally strong. Taken collectively, results of this systematic review suggest that RE is a promising supportive care intervention that results in meaningful improvements in clinically relevant physiologic and QOL outcomes during and following cancer treatment.