Overuse Injuries

Overuse injuries occur when an athlete chronically repeats the same physical task; they may be particularly problematic in adolescent athletes experiencing rapid growth.⁹ In its simplest and most benign form, a heel blister caused by the rubbing of an ill-fitting running shoe is an overuse injury. A more serious form would be, for instance, the constant pounding of legs on hard pavement that causes sufficient vibrational bone stress to induce a stress fracture. This is analogous to taking a wire clothes hanger and bending it repeatedly in the same place. After a while, the hanger develops a crack and eventually breaks. Because endurance athletes spend so many hours training, overuse injuries are a real concern.

A study of triathletes found that some developed skeletal injury early in the competition, which became worse as the competition progressed. These injuries to muscles may alter the use of energy substrates as the triathlon progresses and as the body heals after the competition.¹⁰ Although protein breakdown and muscular damage occur during a race, well-trained athletes should experience no alteration in fitness provided nutrition status is maintained.¹¹ Adequately nourished athletes have a better capacity to heal the minor tissue damage that occurs during training and competition. Additionally, athletes who can maintain carbohydrate and fluid levels during exercise are likely to have better brain function, which translates into a smoother running style that is less prone to injury development. Loss of mental capacity, which can easily occur with either a carbohydrate or fluid storage deficit, causes a breakdown in coordination that can increase structural stresses that lead to injury.