This amount is easily obtained in a diet in which protein comprises 10 to 15 percent of total calories. Complex carbohydrates are found in potatoes, brown rice, dried beans, fresh fruits and vegetables, and whole-grain breads and cereals. These foods also provide dietary fiber, an important element in regulating bowel function. In addition, complex carbohydrates provide the liver and muscle cells with glucose. This is stored as glycogen and converted back to glucose for use when needed during exercise.
Many good books provide detailed dietary and diet supplement-regimens for athletes.
However, beware of advice given by anyone making extraordinary claims for fad foods or for protein, vitamin and mineral supplements. Most of these are not based on sound nutritional research, and are not recommended by nutritionists. Vigorous exercise will replace some body fat with muscle at the same time the body weight remains constant. A strenuous exercise program is accompanied by an increased metabolic rate, requiring an increased caloric intake. If you stop exercising for any reason, be sure to reduce your caloric intake.