Comprised of three unique disciplines (swimming, cycling, and running), triathlon is an endurance sport with growing popularity. Each portion of training and competition contains a significant risk of injury, both from overuse as well as acute injuries. Most overuse injuries involve the lower extremities and may be improved or prevented with proper equipment and mechanics, as well as specialized training programs. Acute injuries include nutritional and gastrointestinal problems, exposure to the elements, and musculoskeletal trauma from accidents.