Do Clories Affect An Athlete's Performance?

When an athlete is training at a high level, a high intake of calories are needed for the athlete to perform. A swimmer will potentially train for upto several hours a day so the individual will need a higher intake of calories in the diet in order to perform at a high level. The athlete may argue that eating junk food doesn't harm their performance.
Consuming a higher intake of junk food may help the athlete reach the sufficient levels of calories needed for training and competition more quickly. Pizza would be a popular choice of food because of the high calorie content. Sports drinks currently on the market would also provide the athlete with a short burst of energy due to the high carbohydrate content. The athlete may also believe that