A reduction of muscle and bone mass, as well as an increase in fat mass, are characteristic changes with increasing age. The term “sarcopaenia” includes an age-related loss of muscle mass and muscle strength. Muscle loss also significantly contributes to the development of various metabolic and mechanical geriatric syndromes (e.g., type 2 diabetes). Sarcopaenia develops from the age of 35 years and leads above all to a decline in type II muscle fibres and an increase of intramuscular lipids. The skeletal muscle also produces various growth factors (IGF-1 and MGF), which have an anabolic effect on the skeleton and also support fracture healing. These “myokines” are above all, demonstrably increased by muscle-building training. In contrast, during physical inactivity and muscular atrophy, myostatin, a negative regulator of muscle mass, leads to muscle loss. Other factors that lead to a decrease in muscle strength and muscle mass include cachexia, AIDS, smoking, protein and vitamin D deficiency, chronic inflammatory processes (e.g. COPD) and glucocorticoids. In addition to sarcopaenia, intramuscular lipid, “myosteatosis,” increases with age and increasing body fatness.