Part 1: Carbohydrates - Carbohydrate Dynamics In Exercise

The intensity and duration of effort and the fitness and nutritional status of the athlete largely determine the fuel mixture in exercise.

The liver increases glucose release to active muscle as exercise progresses from low to high intensity. Simultaneously, muscle glycogen supplies the predominant carbohydrate energy source during the early stages of exercise and as the intensity increases.

Carbohydrate is the preferred fuel during high-intensity aerobic exercise because it rapidly converts into ATP (the cell's unit of energy to make it simple; all the protein, fat & carbo you eat has to be converted into ATP for cell energy) compared to fat and protein. In short intense anaerobic efforts the sole fuel to make ATP is carbohydrates (i.e 200-400 meter sprint). If it is a 100 meter run you just use available ATP already in the cells.

Carbohydrate availability in the metabolic mixture controls its use for energy. In turn, carbohydrate intake affects its availability. High blood glucose will inhibit liver release of its glycogen stores. If blood glucose is high (i,e ingesting fast release carbs prior to exercise) will inhibit oxidation (burning) of fatty acids in the muscles and transport of fatty acids into the mitochondria (cell's Tenaga Nasional that makes ATP).

(will be away from 17-21 May, 2007). to be continued - Intense exercise vs moderate/prolonged exercise wrt to carbohydrate dynamics.