To reach the goals of living longer in better medical conditions, many countries reach the same conclusion: new strategies have to be developed to avoid, or at least limit, the effects of age; this requires a better knowledge of the mechanisms of aging. Our project focuses on the loss of muscle mass associated with aging, called sarcopenia. Sarcopenia unavoidably leads to impaired mobility and poor balance, which contributes to loss of functional autonomy and to increased prevalence for severe falls. Skeletal muscle also plays a central role as a reserve for energy and amino acids. Hence, sarcopenia further triggers severe side metabolic effects such as frailty among elderly persons. The precise mechanisms of muscle aging are still mostly unknown, although many theories have been proposed.