The number of healthy older individuals who are active in sports has increased significantly during the past generation. These individuals continue to perform at a high level, although there appears to be a loss in functional capacity that cannot be overcome by training. No accepted theory of aging exists, but older athletes may be limited primarily by the inability to maintain the same volume and intensity of training. Also, older athletes appear to respond more slowly to the same training load than do younger athletes. The principles of training in older athletes are similar to those in young athletes; however, additional days of recovery and cross training may be necessary to prevent orthopedic injuries. Strategies for maintaining exercise intensity, including resistance training, are advisable to prevent sarcopenia and selective loss of type II muscle fibers.