Despite multi-modal prehabilitation (nutrition, exercise, and psychosocial interventions), 60% of older elective colorectal cancer surgery patients with poor physical function were unable to reach a minimum preoperative 400m six-minute walking distance (6MWD), a prognostic cut-point. Compared to the patients that attained >400m 6MWD preoperatively, twice as many of <400m patients were malnourished. Malnutrition has long been associated with worse functioning (e.g., physical, immune). The investigators hypothesize that for nutritionally deficient patients, the etiology for their poor physical function is malnutrition. Correction of malnutrition alone might thus be sufficient to achieve a 400m 6MWD before surgery and improve patient outcomes.

The investigators propose a randomized controlled trial of nutrition prehabilitation alone vs nutrition prehabilitation with supportive exercise in patients with malnutrition and 6MWD <400m before elective colorectal surgery. The primary objective, and therapeutic target, will be achievement of minimal clinical important difference for the 6MWD (14m for within group comparisons and 19m between groups). Ability to adhere to the interventions will be monitored. The findings of this study will guide optimal treatment for this vulnerable population by exploring the role of nutrition alone vs. nutrition with exercise to optimize surgical outcomes.

Inclusion Criteria:

• Patients aged 65 years and older;
• Patients with cancer scheduled for primary colorectal resection;
• Patients with 6MWD at baseline less than 400 m;
• Patients with Patient-Generated Subjective-Global Assessment (malnutrition assessment) score equal or greater than 9.

Exclusion Criteria:

• Patients with history of premorbid conditions that contraindicate exercise including dementia, -Parkinson's disease or previous stroke with paresis;
• Metastatic cancer;
• Patients who do not speak English or French and cannot be accompanied by someone who speaks English or French;