Adults who are overweight or obese are typically prescribed a calorie-restricted diet and physical activity to promote weight loss and improve health. The manner in which physical activity is prescribed and monitored may influence physical activity engagement. Within the context of clinical research, physical activity has been prescribed in either a supervised or unsupervised manner. Supervised physical activity is typically done in a health-fitness facility under the direct supervision of trained staff. The alternative, unsupervised physical activity, promotes physical activity participation in a setting that is convenient to the individual. Unsupervised activity can be done in any environment or at any time that best suits the individual. Knowing the effects of unsupervised physical activity is important because of the translation of this type of physical activity to non-research settings. Therefore, knowing the magnitude of the physiological effects of unsupervised physical activity compared to supervised physical activity at the same prescribed intensity and dose is of clinical and public health importance. This study is designed to provide insight on these important research questions that can inform future research and the application to clinical, public health, and health-fitness settings.