Impact of resistance training on fatigue among breast cancer patients undergoing chemotherapy: a systematic review and meta-analysis.

Purpose: The effects of aerobic exercise interventions for reducing fatigue after cancer treatment are well-established, and the effect of resistance training remains uncertain. Therefore, this systematic review and meta-analysis aim to analyze the effect of resistance training and combined resistance and endurance training on cancer-related fatigue (CRF) in breast cancer patients.

Methods: A systematic search for randomized controlled trials (RCTs) was conducted on the PubMed, SPORTDiscus, Embase, and Cochrane databases, focusing on the effect of supervised resistance training and combined supervised resistance and endurance training on CRF. Random-effect models were employed for calculating the standardized mean difference (SMD). Risk of bias was assessed with risk of bias 2 (RoB2), and certainty of evidence was judged according to the GRADE approach.

Results: A total of 9 RCTs with 1512 participants were included, and data from 866 participants in 8 RCTs were used for the meta-analysis. The risk of bias was deemed low in seven studies, while one study exhibited attrition bias, and one showed possible selection bias. Resistance training probably reduce the total fatigue (SMD= -0.30, 95% CI -0.52, -0.08, p=0.008), with individual studies showing small effects on physical and emotional CRF. A combined resistance and endurance training reduce total fatigue (SMD= -0.34, 95% CI -0.51, -0.17, p= 0.0001), with individual studies indicating moderate effects on physical fatigue, in daily life fatigue, and small effects on emotional and cognitive CRF.

Conclusion: Both supervised resistance training and combined resistance and endurance training have a small effect on total CRF. There is a trend towards an influence of intensity, with higher intensity potentially resulting in lower total CRF.