What type, amount, and intensity of physical activity is good for your health? How much exercise is too much? Can avoiding physical activity make you ill or lead to premature death? This crisply written and thought-provoking book examines such issues to give readers the first integrated and consolidated introduction to what is known about the impact of physical activity on health. By selectively highlighting some of the best and most important research in physical activity, the authors synthesize studies and theory from several disciplines. They use a behavioral-epidemiology framework to organize the book and explore such topics as: physical activity and the health of children, adolescents, and the elderly; physical activity and its impact on mental health; the role of physical activity in prevention of particular diseases; health risks of physical activity; and how much physical activity is enough and how to measure it; how to promote physical activity and community-based physical activity interventions. Throughout the book, the authors offer studies of diverse populations, including different ethnic backgrounds and nationalities, and different gender groups, and different socioeconomic levels. Although the health benefits of physical activity are fairly well-known, this book furthers our understanding of how to help people become active enough to enjoy these benefits.