The glycaemic Index (gI) ranks foods based on the speed at which the carbohydrate they contain enters the blood stream. Foods may be classified as low (GI <55), moderate (GI 55-70) or high GI (GI >70). It is calculated based on ingestion of 50 g carbohydrate value of the food and not the average serving sizes Also, the GI values commercially available are largely based on test using single foods and not a mixed meal. The glycaemic index value of a food item is affected by the presence of additional food ingredients such as protein and fat in a meal. Each athlete must judge the benefits and the practical issues associated with pre-exercise feedings in their particular situation. The glycaemic index of a meal/snack may be a consideration for some athletes. These include those who may not be able to consume carbohydrate during a prolonged event; they may find it useful to choose a menu based on low gI carbohydrate foods to promote a more sustained release of carbohydrate throughout exercise. However, there is no evidence of universal benefits from such menu choices. In the overall strategies, pre-event eating needs to balance a number of factors such as palatability, portability, cost, intestinal tolerance, ease of preparation and overall nutritional value of the meal.