Good bone health is important to everyone, regardless of age. Osteoporosis is a preventable disease, and steps for increasing bone mass should begin at an early age. To increase bone mass, much of the recent evidence suggests that the best time for intervention with calcium or exercise may be during the prepubertal years. In the older female athlete, BMD is typically well above normal, but even young amenorrheic athletes can have bone density values equal to that of an elderly osteoporotic woman. Myriad treatment options are available for the person with low bone mass, but prevention is a much more preferable alternative.