BACKGROUND: Obesity is a global epidemic and Canada has one of the highest obesity rates in westernized countries. Obesity has many health related complications, including high blood pressure, high cholesterol, diabetes, sleep apnea and osteoarthritis. Bariatric surgery is the most effective way of achieving long-term weight loss and treating the complications of obesity. There is good evidence to support the relationship between physical activity and weight loss following bariatric surgery. While the period leading up to surgery is considered an important opportunity for lifestyle modification, evidence to support recommendations for a supervised preoperative exercise intervention is lacking.