Short-term pre-operative high-intensity interval training does not improve fitness of colorectal cancer patients.

Background: Pre-operative cardiorespiratory fitness (CRF) in colorectal cancer (CRC) patients has been shown to affect post-operative outcomes. The aim of this study was to test the feasibility of high-intensity interval training (HIIT) for improving fitness in pre-operative CRC patients within the 31-day cancer waiting-time targets imposed in the UK.

Methods: Eighteen CRC patients (13 males, mean age: 67 years (range: 52-77 years) participated in supervised HIIT on cycle ergometers 3 or 4 times each week prior to surgery. Exercise intensity during 5 × 1-minute HIIT intervals (interspersed with 90-second recovery) was 100%-120% maximum wattage achieved at a baseline cardiopulmonary exercise test (CPET). CPET before and after HIIT was used to assess CRF.

Results: Patients completed a mean of eight HIIT sessions (range 6-14) over 19 days (SD 7). There was no significant increase in VO peak (23.9 ± 7.0 vs 24.2 ± 7.8 mL/kg/min (mean ± SD), P = 0.58) or anaerobic threshold (AT: 14.0 ± 3.4 vs 14.5 ± 4.5 mL/kg/min, P = 0.50) after HIIT. There was a significant reduction in resting systolic blood pressure (152 ± 19 vs 142 ± 19 mm Hg, P = 0.0005) and heart rate at submaximal exercise intensities after HIIT.

Conclusions: Our pragmatic HIIT exercise protocol did not improve the pre-operative fitness of CRC patients within the 31-day window available in the UK to meet cancer surgical waiting-time targets.