Effect of two different pre-operative exercise training regimens before colorectal surgery on functional capacity

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.