Exercise Training Study Before Bariatric Surgery

The goal of this clinical trial is to figure out if 8 weeks of walking exercise before bariatric surgery improves risk factors for diabetes and other markers of health. This is important as it may help reduce complications after surgery, improve health markers and increase physical activity levels after surgery (which is an important marker of maintaining bariatric weight loss). The main question that this study is trying to answer is whether walking improves a risk factor for type 2 diabetes called insulin sensitivity (how well your body is able to use glucose). Adults planning to have bariatric surgery will be recruited from the Charlottesville VA area. Before they have their surgery, participants will be randomly assigned (like flipping a coin) to a group that participates in 8 weeks of walking on a treadmill (2-3 times a week) or a group that does their normal care before bariatric surgery. Researchers will compare the effects of walking before bariatric surgery on: * Insulin sensitivity (diabetes risk factor) * Health of blood vessels * Rate of complications after surgery * Weight * Body Fat * Fitness level