Clearly the dietary requirements of a marathon runner would be different from a sprint athlete. These differences arise from the way the muscles work in a sprint event versus an endurance event. How does diet of an athlete influence performances is the issue addressed in this problem.
There are two main sources of fuel for exercise: carbohydrates and fats. The energy supply from carbohydrate and fat has an inverse relationship. High rates of carbohydrate usage decrease the combustion of fat. Carbohydrates are used preferentially at very high efforts, such as a 5K race, or at low fitness levels when fat metabolism is underdeveloped.
Conversely, when one teachs the body to rely on fat for fuel, the combustion of carbohydrates goes down, thus "sparing" carbohydrates. This benefits performance in endurance events. One becomes very fatigued when running too low on carbohydrates. We store only a very limited amount of carbohydrate (glycogen) in our bodies. Compare this with a relatively unlimited supply of fat. Even an athlete with only 6 percent body fat will have enough fat to fuel exercise lasting for many hours. When you use more fat, you generate more energy and your carbohydrate supply lasts longer.
There has been lot of research in the past decade on the effect of diet composition on endurance. Until now, endurance athletes usually followed a ...