The desire and necessity for dietary supplements and substances enhancing performance is as historic as sports. The use of supplements dates back to around 500 B.C. when athletes and warriors would add the livers of deer and hearts of lions to their diet hoping that it would enhance their performance. It was believed that the supplements would make them braver, faster, and stronger. Research work conducted in the early twentieth century shows evidence for the link between dietary supplements and improved performance. This was possible because research gave man a better understanding for how muscles worked and how fuel was used during exercise. The roles of protein, carbohydrates, and fats were also better understood and all this led to more research on dietary enhancement supplements.
The importance of taking supplements following intense exercise is based on the necessity for quicker replenishment of muscle glycogen post workout. By taking a protein, carbohydrate, or protein-carbohydrate supplement after exercise, there is a quicker return to performance capacity and this is important for one under continuous exercise.
Numerous studies on restoring muscle glycogen stores have been conducted. They all address the questions of timing, when to take the supplement; amount of supplementation, specifically gram intake of supplement per day; and the type of supplement to take. In comparing various studies done on the difference between a carbohydrate supplement and a carbohydrate-protein supplement, there is plenty of data suggesting the effect of a carbohydrate-protein supplement to be more effective in restoring muscle glycogen.
The recommended intake of protein in people over the age of 18 years is 0.8g per kilogram body weight. This value is the Dietary Reference Intake and is similar to RDA values. In 2000, The American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada performed research and concluded that the value of protein intake is much greater for those individuals that are very active. Their data suggests that endurance athletes should be consuming 1.2-1.4g of protein per kilogram body weight a day and those doing resistance training could even need 1.6-1.7g per kilogram body weight a day. To avoid supplement abuse , these athletes need more protein in their diet because of their intense training and elevated levels of protein synthesis.