<qa>  What is the purpose of the proposed research?DHEA declines dramatically with age. Low DHEA levels have been found to correlate with sarcopenia and osteopenia. It is, therefore, postulated that many physiologic changes of aging are secondary to the decline in DHEA. Thus, the objective of the proposed research is to evaluate the effect of DHEA replacement on age-related changes in body composition, muscle function and metabolism, and bone mass in healthy older adults. The specific aims are to evaluate the effects of DHEA replacement 50 mgd alone, or in combination with resistance exercise training on: a lean body mass, intraabdominal fat and thigh muscle volume, and muscle protein synthesis rate b bone mineral density BMD of the total body, lumbar spine, and hip and biochemical markers of bone turnover and c insulin sensitivity. It is hypothesized that DHEA administration will have additive or synergistic effects with exercise. Healthy but sedentary subjects , aged 65-78 years old, will be randomized to receive either DHEA, 50 mgd, or placebo and to participate in either supervised or home exercise training programs. The supervised exercise program will consist of resistance training designed to increase muscle mass, strength, and bone mass, and decrease fat mass. The goal of this research is to provide information on the potential role of DHEA replacement therapy in maintaining the physical health and functional capacity of older people 