Carbohydrate Metabolism During Exercise

Abstract

Abstract Carbohydrate (CHO) is the main fuel source utilized during moderate to high-intensity exercise and high CHO availability continues to be the platform for contemporary applied sport nutrition guidelines. This chapter begins by providing an overview of glycogen storage before discussing the regulation of CHO metabolism during exercise. Specific attention is provided to regulatory points of control of CHO metabolism in relation to varying exercise intensity, duration, substrate availability, and training status. In these instances, it is clear that both hormonal control and allosteric regulation of key regulatory enzymes can interact to modulate the rates of muscle glycogenolysis, glucose uptake, and CHO oxidation rates. On the basis of such metabolic regulation, an overview of dietary CHO guidelines (both endogenous and exogenous CHO availability) for athletic populations is then presented as well as contemporary thoughts on the role of muscle glycogen availability on regulating skeletal muscle adaptations to endurance training. The latter topic is now an intense area of investigation that is likely to dominate applied aspects of exercise metabolism research over the next decade. Despite over 100 years of research, it is clear that the study of only 500\xa0g of substrate remains as exciting as ever.