Children can be seemingly invincible, with inexhaustible energy. Even the elite young athlete, however, may lack the experience to realize when his or her level of activity is increasing the risk of sustaining injuries related to overuse. Coaches, trainers, parents, and physicians need to monitor the activities of young athletes, modify factors that may place them at increased risk of injury, and enforce periods of "relative rest" when necessary. Factors that can increase the risk of overuse injuries can be identified and modified if possible. Environmental factors include the use of sport-specific equipment (ie, running shoes instead of cleats for running activities) and properly sized equipment. Children of the same age will be of different sizes; "one size fits all" is not a good enough policy in this diverse population. Training factors include magnitude, frequency, and intensity. Children should be asked if they are participating in more than one team or sport simultaneously. Also, because the child's interest may exceed his or her skill level, young athletes optimally should be taught sport-specific skills to prevent injuries related to improper biomechanics. Finally, anatomic factors should be assessed, including alignment, laxity, flexibility, and muscle balance. These factors cannot always be changed, but coaches can modify training regimens and suggest strength and flexibility training to counteract specific weaknesses. Young athletes have a long future of activity ahead of them. Even if they never reach the Olympics or compete in the National Basketball Association (NBA), the injuries that occur in young athletes can have significant repercussions long after they leave the competitive arena.