Effectiveness of resistance training in preventing sarcopenia among breast cancer patients undergoing chemotherapy: A systematic review and meta-analysis

BACKGROUND: Breast cancer patients undergoing chemotherapy experience body composition changes impacting treatment outcomes. The role of resistance training in mitigating chemotherapy-induced sarcopenia in breast cancer patients is not well defined.

AIMS: This study aims to assess the efficacy of resistance training in preventing sarcopenia among breast cancer patients undergoing chemotherapy.

METHODS: A systematic search was conducted across PubMed, EMBASE, Medline, the Cochrane Library, and CINAHL until May 5, 2023. Selected literature focused on the effects of resistance training on body fat, muscle mass, muscle strength, and physical performance in breast cancer patients undergoing chemotherapy. Cochrane Risk of Bias tool version 2.0 was employed for quality assessment, and data were analyzed using Comprehensive Meta-Analysis version 2.0.

RESULTS: Eleven randomized controlled trials (RCTs) showed that resistance training had a significant positive impact on reducing body fat (SMD = -0.250, 95% CI [-0.450, -0.050]), increasing lean body mass (SMD = 0.374, 95% CI [0.178, 0.571]), and enhancing handgrip strength at both the affected site (SMD = 0.326, 95% CI [0.108, 0.543]) and the nonaffected site (SMD = 0.276, 95% CI [0.059, 0.492]). Additionally, significant improvements were observed in leg press strength (SMD = 0.598, 95% CI [0.401, 0.796]) and overall physical performance (SMD = 0.671, 95% CI [0.419, 0.923]).

LINKING EVIDENCE TO ACTION: Resistance training is a recommended intervention for reducing body fat, increasing muscle mass, muscle strength, and enhancing physical performance in breast cancer patients undergoing chemotherapy. Ideal low-intensity resistance training programs span 8-24 weeks, with 20-to-90-min sessions 2-4 times weekly. Regimens generally entail 8-12 repetitions at 40%-90% of one-repetition maximum test, with free-weight resistance training targeting major muscle groups yielding substantial benefits. Further research should explore outcomes across different chemotherapy phases and investigate long-term resistance training effects for a comprehensive view.