Effect of two different pre-operative exercise training regimens before colorectal surgery on functional capacity: A randomised controlled trial.

BACKGROUND Multimodal prehabilitation, including exercise training, nutritional therapy and anxiety reduction, has been shown to attenuate functional decline associated with surgery. Due to the growing interest in functional status as a targeted surgical outcome, a better understanding of the optimal prescription of exercise is critical. OBJECTIVE The objective is to compare peri-operative functional trajectory in response to two different exercise training protocols within a 4-week, supervised, multimodal prehabilitation programme. DESIGN This was a single blinded, single centre, randomised controlled study. Participants performed four assessments: at baseline, after prehabilitation (just before surgery), and at 1 and 2 months after surgery. PATIENTS Adult patients scheduled for elective resection of nonmetastatic colorectal cancer were included provided there were no absolute contraindications to exercise nor poor language comprehension. INTERVENTION Patients followed either high-intensity interval training (HIIT), or moderate intensity continuous training (MICT), as part of a 4-week multimodal prehabilitation programme. Both groups followed the same supervised resistance training, nutritional therapy and anxiety reduction interventions. All patients followed standardised peri-operative management. MAIN OUTCOME MEASURE Changes in oxygen consumption at anaerobic threshold, measured with sequential cardio-pulmonary exercise testing, were assessed and compared between groups. RESULTS Forty two patients were included in the primary analysis (HIIT n = 21 vs. MICT n = 21), with mean ± SD age 64.5 ± 11.2 years and 62% were men. At 2 months after surgery, 13/21 (62%) in HIIT and 11/21 (52%) in MICT attended the study visits. Both protocols significantly enhanced pre-operative functional capacity, with no difference between groups: mean (95% confidence interval) oxygen consumption at anaerobic threshold 1.97 (0.75 to 3.19) ml kg min in HIIT vs. 1.71 (0.56 to 2.85) in MICT, P = 0.753. At 2 months after surgery, the HIIT group showed a higher improvement in physical fitness: 2.36 (0.378 to 4.34) ml kg min, P = 0.021. No adverse events occurred during the intervention. CONCLUSION Both MICT and HIIT enhanced pre-operative functional capacity. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT03361150.