The Effect Of Exercise On Carbohydrate Metabolism

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carbohydrate metabolism important in exercise? Explore the literature to explain the effects of exercise.

Carbohydrates are the body’s source of quick burning fuel, particularly for hard working tissues like the brain, heart and muscle. Blood glucose and muscle glycogen are essential for exercise. The rate of carbohydrate utilization during prolonged exercise is closely related to the energy needs of working muscles. Carbohydrate metabolism is important as the major source of energy during exercise. Carbohydrates metabolise the most efficiently of the body’s sources of energy – after the body’s glycogen stores in the muscle and liver are depleted the body must obtain its energy from fatty acid metabolism and amino acid metabolism which are not efficient and the athlete suffers a dramatic drop in strength and endurance.
The importance of carbohydrates to exercise is emphasised in the phenomenon of “carbo-loading” that is popular with modern elite athletes. The athlete consumes large amounts of carbohydrates in the days before a big event and by the time the race begins, their muscles are full of fast-burning carbohydrates that will enhance their performance and endurance.
Carbohydrate metabolism is also important in exercise as a powerful regulator of fat oxidation. Research suggests that malonyl CoA, elevated during exercise situations associated with high rates of carbohydrate metabolism inhibits carnitine transferase activity, thereby suppressing the entry of fatty acids into the mitochondria. This has important implications for those who exercise to loose fat, for as little as twenty grams of ingested glucose can raise insulin and decrease fat availability and oxidation during exercise. The pre-exercise consumption of even a small quantity of carbohydrate would have a detrimental effect on a weight loss program. Carbohydrate ingestion has been shown to suppress fat oxidation for up to eight hours.
The effect that...