OBJECTIVES: The objective of this study is to measure the short and intermediate-term benefits of a preoperative exercise intervention on patients awaiting publicly funded bariatric surgery in Manitoba. The primary outcome will be improvement in general exercise capacity as measured by change in 6-minute walk test (how far a person can walk on a flat surface in 6 minutes). Other outcomes will include excess weight loss, change in body composition, strength testing and irisin bloodwork & muscle biopsy.