Why do women live longer than men? Does ownership of paired X chromosomes confer more prolonged survival on females, or is the gender difference in life-expectancy a cumulative consequence of differing life experiences for women and men? The areas of gender differences in aging, functional capacity, and the response to physical activity have often been the basis for speculation rather than informed judgment. Gender, Physical Activity, and Aging draws upon the sound knowledge base of leading investigators to provide objective, evidence-based evaluations of particular facets of the aging process. Focusing on gender differences, it examines the rate of aging, loss of functional capacity, disability, and the quality of life among the elderly and presents evidence of potential modification through physical activity and lifestyle.