ABSTRACT
Carbohydrates are an important energy source for human metabolism. The dietary manipulation of carbohydrate intake prior to, during, and after exercise can improve exercise performance largely through optimizing muscle and liver glycogen stores or through the maintenance of blood glucose homeostasis. The 1989 Recommended Dietary Allowance subcommittee recommended that more than half the energy requirement beyond infancy be provided by carbohydrate. In the postprandial state, absorbed macronutrients are used for energy, structural repletion of tissues, and in the case of glucose and fatty acids, stored for use during the postabsorptive state, especially during the overnight fast. The ability of glycolysis to generate adenosine triphosphate (ATP) in the absence of oxygen is of physiological significance because it provides useful energy to working skeletal muscle even when aerobic oxidation is limited. This ATP production also enables tissues with significant glycolytic capacity to survive hypoxic episodes. ATP is the common energy currency used for all cellular biological work.
