When most athletes think of protein, the first that comes to mind is usually whey protein powder. However, there are many types of beneficial protein supplements including whey isolate protein, casein protein, soy protein and egg protein. Protein is what muscle is made of, so it is a very useful and even necessary part of a body builder's diet. It is also useful for vegetarians, those on a strict diet, or anyone else who does not receive enough protein through their regular diet. Protein is very essential, and can be broken down into amino acids to serve a multitude of functions throughout the body. Regular, low doses of protein supplements has been shown to decrease the effects of over-training, and the versatility of the amino acids can help balance out nutrition and blood sugar levels. Each type of protein has its own unique benefits, but the ease of use and overall health benefits come with all protein supplements.