An overview of sarcopenia: facts and numbers on prevalence and clinical impact

Human muscle undergoes constant changes. After about age 50, muscle mass decreases at an annual rate of 1-2%. Muscle strength declines by 1.5% between ages 50 and 60 and by 3% thereafter. The reasons for these changes include denervation of motor units and a net conversion of fast type II muscle fibers into slow type I fibers with resulting loss in muscle power necessary for activities of daily living. In addition, lipids are deposited in the...