Phase 1: Ten candidates for bariatric surgery will be included in this phase. In a pre-training focus group, subjects will be interviewed about their expectations and their availability for a PreSPAT. These results combined with those of the literature will be used to design the PreSPAT. To measure its effectiveness, anthropometric parameters, body composition, physical capacity, motivational stage, perceived benefits and barriers facing physical activity and quality of life will be evaluated before and after the PreSPAT. Subjects satisfaction with the physical activity intervention will be measured with a questionnaire at 6 weeks and at the end of the PreSPAT.