In 1982, the National Research Council noted a link between cancer and protein. Countries with lower-protein diets have lower rates of osteoporosis and hip fractures. 7 Increased calcium excretion increases risk for kidney stones. For a long time it was thought that athletes needed much more protein than other people. The truth is that athletes need only slightly more protein, which is easily obtained in the larger servings athletes require for their higher caloric intake.
Vegetarian diets are great for athletes.
As long as one is eating a variety of plant foods in sufficient quantity to maintain one's weight, the body gets plenty of protein. Protein requirements in humans. Committee on Diet, Nutrition, and Cancer of the National Research Council. Diet, Nutrition, and Cancer. Washington, DC, 1982. 5.