Resistance Exercise for Breast Cancer Patients? Evidence from the Last Decade.

Background: Breast cancer is associated with many therapy-induced side effects that impact patients' lives from diagnosis to long-term survivorship. Physical activity has become an important and proven supportive measure in treating side effects like loss of muscle strength, fatigue, chemotherapy-induced peripheral neuropathy, lymphedema, and loss of quality of life. Resistance training (RT) is an established exercise intervention for breast cancer patients, but the correct type, timing, intensity, and duration of exercise remain unclear. It is necessary to investigate different resistance training interventions and their effects on breast cancer patients by covering all stages of treatment, beginning with prehabilitation, through the period of acute therapy, to long-term survivorship.

Conclusion: Upon evaluation of randomized controlled trials (RCTs) from the past decade, RT was found to be feasible and safe. Furthermore, there is evidence on the impact of RT on muscle strength, CRF and QoL amongst other factors. Studies implementing mixes of aerobic and strength exercises are rather common, but RCTs of RT-only protocols remain scarce. Different strength training protocols at distinct stages of breast cancer treatment have been conducted, but with the complexity of treatments and the variety of training styles, a large field of study remains.

Key Messages: Although the overall data on RT for breast cancer patients has increased, there are many different methodological approaches and testing measures as well as gaps in study documentation. There is still very little of the evidence that would facilitate the compilation of standardized and individualized guidelines.