Whey protein is the most studied supplement after Creatine. It has been proven that protein helps build muscle, with the ideal ingestion time being immediately post-workout, or in your “anabolic window.” The only protein that is able to be digested within 45 minutes is whey due to its purity and chemical properties. Whey usually comes in a few forms: Hydrolysate, Isolate and Concentrate. Isolate is more filtered, and is more quickly absorbed by the body than Concentrate. However, it is important to keep a balance of both, since your muscles have a constant demand for protein.