During athletic training, there are certain needs that must be met in order to turn the body into a high-performance machine; fuel, recovery, and compositional change. All three of these are driven largely if not entirely by proper nutrition. The need for fuel comes in the form of what you eat, as your body transforms the calories in food into energy you can use. A number of calories necessary are different for every person dependent on inherent body factors and lifestyle, increasing as you become more active and athletic. However more important than how many calories you eat is where you are getting them from.
Click on the image to the left to download a sample 4500 calorie diet.