BackgroundOf all older patients that opt for elective colorectal surgery, approximately one-third has one or more postoperative complications, particularly those patients with a low cardiorespiratory fitness (ventilatory anaerobic threshold (VAT) < 11 mL/kg/min). A physical exercise training program prior to surgery (prehabilitation) can improve their cardiorespiratory fitness. It remains to be seen whether prehabilitation also reduces postoperative complications, as most of the studies so far were rather underpowered, heterogeneous, and biased toward selection of patients with a lower risk of postoperative complications. The primary objective of this study is to evaluate the effects of a three-week prehabilitation program on 30-day postoperative complications in patients with a VAT < 11 mL/kg/min planned for elective colorectal resection for colorectal cancer or dysplasia.MethodsIn this multicenter prospective randomized controlled trial, patients ≥ 60 years with colorectal cancer or dysplasia grade I, II, or III, planned for elective colorectal resection in two hospitals in the Netherlands, will be recruited. Eligible patients must have a score ≤ 7 metabolic equivalents on the veterans-specific activity questionnaire, and should be able to perform a cardiopulmonary exercise test. A total of 86 patients will be randomized (block-stratified randomization) to prehabilitation (intervention group) or usual care (control group). For final inclusion, VAT should be < 11 mL/kg/min. Three times a week for 3 weeks, a 60-min supervised prehabilitation session will be completed in community physical therapy practices by the 43 patients in the prehabilitation group, consisting of moderate-to-high intensity interval training to improve cardiorespiratory fitness, and resistance training to improve peripheral muscle strength. Additionally, patients perform home exercises twice a week on a moderate intensity level. The 43 patients in the usual care group will receive usual care.DiscussionOptimizing preoperative physical fitness may decrease the postoperative complication rate, may lead to fewer reoperations, less intense clinical care, a shorter length of stay, a more effective surgical planning (process-optimization), fewer readmissions, less intense rehabilitation, shorter rehabilitation period, earlier resumption of work, enhance patient perceived health-related quality of life, and promote performance in daily life. Cost-effectiveness should therefore be expected and evaluated.Trial registrationMedical Ethics Committee Twente, Enschede, the Netherlands (NL45001.044.13, September 3, 2013); Netherlands Trial Register (NTR; NTR4032, June 14, 2013).