Both groups will be evaluated for exercise tolerance, walking capacity and health and emotional status at enrolment and after 3 three weeks of training as well as at 4 weeks, 8 weeks and 24 weeks (6 months) post-surgery. The main outcome measure will be the 6 Minute Walk Test - a valid and reliable measure of functional walking capacity. The estimator of effect will be the proportion of people in each group who, at 8 weeks post-surgery, achieve or exceed their baseline value on this test (± 20m). The proposed sample size is 200. This is based on 80% power to detect a difference of 22% in the proportion recovering to baseline values (40% in standard and 62% in prehabilitation). The results of this trial will be used to inform practitioners and patients alike of the benefits (or risks if any) of exercise in preparing for surgery.