During exercise our bodies use a mixture of carbohydrates and fats for energy. When carbohydrates are consumed they are stored as glycogen (the storage form of glucose) in the muscles and liver. During exercise these glycogen stores are then converted to glucose which is used to provide energy. Glucose is the bodies preferred energy source especially when performing at a high intensity. This is because it is a more efficient energy source as it can be converted to energy quicker than fat. It is not only required by the working muscles but also by the brain and central nervous system.
When fuel supplies are inadequate this will hinder performance and will result in fatigue occurring earlier. It is therefore beneficial to build up fuel supplies leading up to a race. This is done by increasing carbohydrate intake a few days before a race, as carbohydrates provide a large amount of the energy for endurance exercise. This is known as “carbo loading” and it helps build up glycogen stores within the body so that you have a greater supply of energy. The body is able to store enough glycogen to fuel 90-120mins of moderate intensity exercise (40-50% of VO2 Max), carbo loading will ensure these energy stores are maximised and this will delay the onset of fatigue... Read More