The athlete's diet: a current view.

As a result of new interest in prescribing individual athletic programs and healthy life styles, the average participant and the health care provider are faced with confusing information on what constitutes optimal nutrition. Not only has the efficacy of dietary supplements (high-protein, "megadose" vitamins and minerals) for improved athletic performance not been demonstrated, but these supplements can also have undesirable effects. A diet of adequate calories and composition remains the optimal source of good nutrition and must be balanced with energy output. While most mineral supplements are unnecessary, iron supplements for female athletes and for male long-distance runners may be advisable. Carbohydrate loading is the only dietary manipulation shown to affect athletic performance and then only in the endurance athlete. Conscious water replacement is needed during and after competition.