WRONG!

" Athletes are told to eat a diet high in carbohydrates and low in fats. This, they are told, will increase their performance. However, this was not confirmed in a dietary study published in 1994. (5)

Using three diets: normal, high-fat and high-carbohydrate, the study showed that the high-carbohydrate diet increased performance by an average ten percent over a normal mixed diet. Not bad, you might think, but the high-fat diet increased performance by a massive thirty-three percent. That's much better. The authors conclude that restriction of dietary fat may be detrimental to endurance performance. "
http://www.second-opinions.co.uk/athletic_diet3.html