Exercise, Brain Activity, and Weight Maintenance

Inclusion Criteria: * Age 18-70 years * Body mass index (BMI) \>19 kg/m2 and body weight\< 250kg * Participants must have experienced a clinically significant weight regain, defined as over 10% of their maximum weight lost, within 1 to 5 years following their bariatric surgery. They will be asked to self-report their weight loss history. Participants must also provide the operative report from their bariatric surgery for reference. * In good general health with no conditions that could influence the outcome of the trial, and in the judgment of the investigator is a good candidate for the study based on review of available medical history, physical examination and clinical laboratory evaluations * Willing to adhere to the protocol requirements for the duration of the study Exclusion Criteria: * Type 1 diabetes mellitus * Peripheral neuropathy with insensate feet * Recent blood donation within the last 2 months * Use of beta-blockers * Current pregnancy or breastfeeding * Active Heart or lung disease * Severe hypertension (systolic \>160 mmHg or diastolic \>90 mmHg) * Inability to exercise for any reason * Any known contraindication to exercise testing based on current ACSM guidelines * MRI contraindications, such as presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments, or foreign objects in the eyes, skin, or body * Known presence of a structural brain lesion (e.g. tumor, cortical infarct) * Presence of another neurologic disorder, which could impact findings (e.g. multiple sclerosis) * History of cardiovascular disease, stroke, congestive heart failure * Active hematological, renal, pulmonary or hepatic disorders * Active treatment for cancer * A history of active alcohol or substance abuse * Any significant systemic illness or unstable medical condition which could lead to difficulty complying with the study protocol * History of claustrophobia and inability to tolerate an MRI * Body weight \>250kgr and largest body diameter of 70cm as there is a certain weight and diameter limit of the MRI scanner * Unwilling or unable to return for study visits, undergo neuropsychological testing and MRI imaging * Left-handedness