The term "sarcopenia" is used to indicate the progressive reduction in muscle mass and muscle strength that affects older people, is strongly associated to bone loss and osteoporosis and causes a large percentage of late-life disability. Searching for potential targets for intervention, many studies are currently focusing on the pathophysiologic mechanisms that may explain the development of sarcopenia and its association to osteoporosis. Mechanisms being studied include physical inactivity, oxidative stress, chronic inflammation and general changes in body composition.