Supervised high-intensity interval training reduces the negative effect of chemotherapy on cardiorespiratory fitness in young breast cancer women: a randomised controlled study.

Purpose: Younger women are diagnosed more often with aggressive breast cancer (BC) subtypes, the treatment of which usually incorporates chemotherapy. Physical training plays a significant role in mitigating the adverse effects of systemic cancer therapy, improving quality of life, and potentially enhancing treatment efficacy. High-intensity interval training (HIIT) emerged as a promising intervention to counteract the fatigue induced by chemotherapy, which in younger women often causes depression and disruption of employment. This study aimed to investigate whether supervised HIIT employed concurrently with chemotherapy impacts the cardiorespiratory fitness of young BC patients.

Methods: Twenty-six young (18-40 years old) BC patients scheduled for chemotherapy were randomised to intervention comprising supervised HIIT employed concurrently with chemotherapy or no supervised training (control) for 6 months. Outcomes measured using cardiopulmonary exercise testing (CPET) and non-invasive cardiac output testing were cardiorespiratory fitness and cardiac output.

Results: Compared to control, employment of HIIT mitigated the decrease in relative peakVO₂ from 33.630 to 29.540 ml/kg/min for HIIT group and from 29.679 to 22.571 ml/kg/min for control group (ANCOVA p = 0.018, ES = 0.469), and also a mitigated the decrease in exercise time from 685.600 to 666.500 s for HIIT group and from 703.357 to 555.500 s for control group (ANCOVA p = 0.008, ES = 0.815) measured during CPET.

Conclusions: Supervised HIIT implemented alongside chemotherapy can mitigate the decline in cardiorespiratory fitness caused by BC chemotherapy in young patients.

Trial registration: The study was registered in the clinicaltrials.gov registry (#NCT06190600) on 2024-01-05, retrospectively registered.