The developing musculoskeletal structures of the immature athlete are uniquely susceptible to injury, particularly at the physes. These growth plates are present in arm and leg bones, and some may not close until the late teen years. Early literature suggested that weight training might be inappropriate for these athletes. However, recent evidence suggests that, properly done, strength/resistance training may not only be safe, it may also help reduce the risk of injury for the young athletes. Nurses are often called upon to advise coaches of formal and community athletic programs, and need to know the underlying physiology of developing bone and muscle as well as the current recommendations related to training.