There is no supplement source older yet more misunderstood than protein or amino acids. Basically, there are four general sources of amino acids:
1. Protein from foods such as meats, grains and vegetables. These sources are widely available and taste good. On the negative side they may spoil quickly, contain risky microorganisms, have high levels of fat or carbohydrates, be highly fibrous and tougher to digest, cause allergies and denature during cooking.
2. Intact proteins concentrates which are 80% pure or food isolates which are normally 90% pure. These are simple food extracts and ordinarily taste and mix well. On the down side, allergies are still possible with their use and depending on the quality of the product it may have high levels of fat or sugar and an absence of important individual amino acids such as glutamine.
3. Protein hydrolystates which are often refereed to as peptide or short protein chain aminos. Protein hydrolysates are completely pure with no fat or sugar, hypoallergenic, very “friendly” digestively and possess the fastest amino uptake of any protein.
4. Single free form aminos which are manufactured through fermentation by microorganisms in large biological chambers. These can be manufactured as pharmaceutical grade pure injectables but are very costly, taste terrible, have poor mixability, high digestive irritability and relatively slow during absorption.
Modern protein research has demonstrated beyond doubt that for normal non injectable use, protein hydrolysates are far better than other sources for use by the muscles. In fact they normally absorbed twice as fast as other sources including isolates.
And, similar to a foot race, speed is critical for protein absorption and muscle cell utilization. In order to best understand this, it is important to know how the body treats protein from mouth to muscle.
After swallowing, large proteins are chopped into small pieces in the stomach by acids and enzymes. The result are refereed to as oligopeptides and are chains 4-6 aminos long. This process is not terribly efficient and depending on the situation might take some time.
After passing through the stomach, enzymes on the surface of the small intestine chop the oligopeptides into smaller chains 1-3 aminos long. These are refereed to as single, dipeptide or tripeptide aminos, depending on their length. These small aminos then enter the small intestine cells by crossing the outer cell membrane. In order to cross the cell membrane, receptor sites must be utilized. Intestinal cells are very receptor selective. Absorption will not occur unless the right length amino binds to the proper amino receptor site. The small intestine has many single amino receptors but far more di- and tri-peptide receptors.
All receptor sites work equally fast. After making their way into the small intestine the dipeptide and tripeptides are instantaneously chopped into single amino by internal intestinal enzymes. The single aminos are then dumped into bloodstream where the muscle cells will choose which single aminos they need.
Why the rush? More aminos in the blood (especially with insulin present) means more aminos in the muscle. This increases protein synthesis which stimulates recovery and tissue repair or growth.
As you can see, larger proteins such as foods, isolates or concentrates must go through additional sometimes lengthy digestive processes before making it to the intestinal membrane. And single free form aminos, although making it the small intestine rather fast, run into absorption delays in that they can only be picked up for transport across the membrane by single amino receptors. This, of course, is terribly inefficient as compared to di- and tri- peptide hydrolystates which can be transported more quickly and efficiently. If you have trouble with this concept, imagine admitting a line of movie patrons to a theater through one door one at a time. Then imagine keeping that same door open but also opening six additional doors that would admit people two and three at a time. Obviously, there is no question as to which line would end up getting into the theater faster. The same is true of di- and tri peptide aminos versus free form aminos.
In conclusion, then, the best protein for an athlete to take after training is without question a di- and tri-peptide hydrolystate. This protein will enter the bloodstream far faster than any other source and will be more available to the muscles for recovery and growth.