Decreased skeletal muscle mass is a prevalent condition among the elderly, and an important cause of disability and functional decline. The declines in muscle mass associated with aging may be related to alterations in specific kinds of growth factors in the muscle. Elderly hip fracture patients often have significant decreases in muscle mass. The purpose of this study is to investigate whether an exercise program can induce changes in muscle growth factors that are associated with increases in muscle mass and strength in elderly hip fracture patients.