Thirty adults will be randomized into 2 groups: CON or EXC. The patients of ECC group will follow habituation sessions (2weeks) to avoid the secondary muscular effects of high intensity eccentric exercise. The training program will last 12 weeks for the two groups. Before and after, each subjects will participate to the following measurements: total and segmental body composition (DXA), aerobic capacities (maximal incremental exercise test, VO2max), muscular lower limbs strength (isometric end isokinetic dynamometer), rest energy expenditure (indirect calorimetry), biological parameters (lipid profile, insulin-resistance), physical activity (actimetry), food intakes and quality of life (questionnaires).