Improvement in Physical Performance and Obesity Surgery in Patients Older Than 60 Years

Inclusion Criteria: Criteria specific to the study Subjects aged 60 or over and younger than 75 yrs., seeking obesity treatments, seeking obesity surgery, with a BMI of 30 kg/m² or more, with comorbidities (see below), and a mildly decreased physical performance (SPPB between 5 and 8) are considered to participate in the study Criteria specific to obesity surgery This projects extends the classical recommendation for obesity surgery to people with a BMI of 30 and over with either the comorbidities list below, or a SPPB between 5 and 8. This level of physical impairment can be considered as a comorbidity in the elderly. The French Ministry of health (HAS) recommends that obesity surgery be considered (here with a gastric banding) in patients fulfilling the following criteria: * Subjects with a BMI of 40kg/m² or more, or 35kg/m² or more if at least one comorbidity that can be improved by weight loss is present among hypertension, obstructive sleep apnea, severe metabolic disorder (such as type 2 diabetes, NASH), or rheumatologic conditions associated with disability. * After the failure of well designed medical, dietetic, psychological intervention followed up for 6-12 months, with no sufficient weight loss or in case of the failure of maintaining weight loss * In subjects well informed of the consequences of surgery, and after a multi-disciplinary evaluation * Subjects have understood and accepted the need for a long term medical and surgical follow up * The risk of surgery is acceptable * patient who signed the informed consent * patient affiliated to a social security cover or equivalent Exclusion Criteria: Criteria specific to the study * These are the impossibility to follow a physical training (unstable coronary heart disease, severe lung function impairment, rheumatologic conditions preventing training, a SPPB score below 5, cancer treatment within the 3 last months, Parkinson's disease, other severe illness that may interfere with physical activity) Criteria specific to gastric banding * Cognitive impairment (MMSE ≤ 25) * Severe eating disorder * Impossible long-term follow-up * Alcohol or drug dependence * Lack of previous well designed obesity care * Vital prognosis engaged in the short term * Contra-indications to anaesthesia Classical criteria for the non inclusion in a trial * The subject is in jail, or has freedom restriction * Guardianship curators or judicial protection * Patients participating in another intervention study.