Many compounds, nutrients, and foods have been claimed to provide increased performance but the evidence is not always present to support these claims. The benefits of carbohydrate loading and the value of specific beverages in providing optimum hydration are well known but other substances are emerging as potentially beneficial to performance. Requirements may be as high as 1 to 1.6 grams per kilogram to maintain positive nitrogen balance. FAT - Many athletes attempt to limit the total fat in their diets. While the majority of Americans might be better off without a high level of fat intake, there are minimum amounts needed for performance.
Triglycerides provide a significant proportion of energy at all intensities of physical activity.
Females on extremely low fat intakes participating in high levels of physical activity may become amenorrheic and suffer increased bone mineral loss. Vitamin C has been shown to reduce soreness when taken three times per day for three days prior to an event and five, seven and eight days afterward. The down side is the potential to induce kidney stones in those individuals prone to gout and the elimination of the ergogenic effects of creatine. Vitamin E provides protection against exercise-induced oxidative injury and also helps maintain the immune response. The down side of caffeine is the sensitivity of some individuals and the increased diuresis, anxiety, nervousness, and potential arrhythmia.