Feasibility of high intensity interval training in patients with breast Cancer undergoing anthracycline chemotherapy: a randomized pilot trial

BACKGROUND: Anthracycline-based chemotherapy is associated with reduced cardiorespiratory fitness in breast cancer patients. High intensity interval training (HIIT) induces greater benefits on cardiorespiratory fitness than moderate continuous aerobic exercise in patients with heart failure. The study purpose was to determine whether a HIIT intervention is a feasible exercise strategy for breast cancer patients undergoing anthracycline-based chemotherapy. METHODS: Thirty women were randomized to either HIIT or non-exercise control group (CON). Participants performed a maximal cycling fitness test to measure peak power output during maximal oxygen uptake (VO(2)max). The HIIT group participated in an 8-week HIIT intervention occurring 3 times weekly. Feasibility was calculated by computing (1) the average weekly minutes of HIIT over 8 weeks and (2) the number of sessions attended and multiplied by 100 (percentage of sessions). The intervention was considered feasible if more than 50% of participants completed both an average of 70% of weekly minutes (63/90 min) and attended 70% exercise sessions (17/24 sessions). RESULTS: Participants were 46.9 ± 9.8 (mean ± SD) years old, diagnosed with clinical stage II (30%) or III (63%) breast cancer. The average weekly minutes of exercise completed was 78 ± 5.1 out of 90 min. Twelve of 15 participants met both feasibility criteria, attending 19.2 ± 2.1 out of 24 sessions (82.3%). VO(2)max was maintained (19.7 ± 8.7 to 19.4 ± 6.6 ml/kg/min) in HIIT group (p = 0.94) while there was a significant decrease in VO(2)max (18.7 ± 7.1 to 16.1 ± 6.0 ml/kg/min) in CON group from baseline to 8 weeks (p = 0.001). CONCLUSIONS: HIIT is a feasible exercise intervention to maintain VO(2)max in breast cancer patients receiving anthracycline-based chemotherapy. TRIAL REGISTRATION: The protocol and informed consent were approved by the institutional IRB (HS-12-00227) and registered (ClinicalTrials.gov NCT02454777; date of registration: May 272,015).