High-intensity interval training in breast cancer survivors: a systematic review

BACKGROUND: To review the settings and outcomes of high-intensity interval training (HIIT) interventions for breast cancer survivors, and to explore the feasibility of prescribing exercise for breast cancer survivors. METHODS: A systematic search of electronic databases was conducted for studies published up to May 31, 2020. Eligibility criteria included randomized controlled trials of HIIT intervention in breast cancer survivors. Studies were grouped by whether the intervention was conducted during or after breast cancer treatment, and intervention methods and outcomes were reviewed within each group. RESULTS: Twenty-six studies were identified, and 13 satisfied the inclusion criteria. Intervention was conducted during treatment in 8 studies, and after treatment in 5. Intervention duration ranged from 3 to 16 weeks, with 2 or 3 sessions per week, for a total of 9 to 36 sessions. All interventions were supervised; 12 were lab-based, and 1 was community-based. One of most promising outcomes was improvement of cardiorespiratory fitness by HIIT. CONCLUSION: This review found that all studies on HIIT for breast cancer survivors investigated lab-based, supervised interventions, but not home-based or unsupervised. HIIT is a time-efficient method for increasing cardiovascular function in breast cancer survivors, but further research is necessary to determine its effects on other outcomes.