Despite advances in surgical care, the incidence of postoperative complications and prolonged recovery following colorectal surgery remains high. Efforts to improve the recovery process have primarily focused on the intraoperative (eg, minimally invasive surgery, afferent neural blockade) and post-operative periods (eg, "fast track" early nutrition and mobilization. The pre-operative period may in fact be a better time to intervene in the factors that contribute to recovery. The process of enhancing functional capacity of the individual in anticipation of an upcoming stressor has been termed "prehabilitation". Based on the notion that preoperative exercise would have an impact on recovery of functional capacity after colorectal surgery, our group recently conducted a randomized controlled trial. Subgroup analysis identified that patients whose functional exercise capacity improved preoperatively, regardless of exercise technique, recovered well in the postoperative period. However, one-third of patients deteriorated preoperatively despite the exercise regimen, and these patients were also at greater risk for prolonged recovery after surgery. These results suggested that exercise alone is not sufficient to attenuate the stress response in all patients. In the present trial, the impact of a multimodal prehabilitation intervention composed of exercise, nutritional supplement and psychological well-being begun in the preoperative period will be compared to one begun in the postoperative period.

Inclusion Criteria:

• referred for scheduled surgery for nonmetastasized colorectal cancer
• age > 18 years old

Exclusion Criteria:

• asa 4-5
• Poor English or French comprehension
• severe co-morbid disease interfering with ability to perform exercise at home or complete testing