What are the benefits and problems associated with amino acid supplements?

What are the benefits and problems associated with amino acid supplements, particularly a supplement with a wide variety of amino acids, for an individual on a heavy workout schedule and a high carbohydrate diet? I have heard that L-tryptophan supplements are associated with a blood disease, is this true?

Tryptophan is an essential amino acid when taken as a supplement can make a person sleepy. Turkey is high in tryptophan and do you remember how a turkey dinner makes people sleepy? Tryptophan is not associated with a blood disease.

Phenylalanine is another essential amino acid that isn’t metabolized very well by children and adults with PKU. Is this the blood disease you were thinking of? PKU is genetically passed from parent to child.

There is no research to support any benefit of taking amino acid supplements for persons who exercise. Amino acids are either essential (8 can’t be made by the body and must come from a source outside the body) or non-essential (12 that can be made within the body from essential amino acids). If you take an amino acid supplement, make sure it contains only essential amino acids (isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine) or you are wasting your money. Amino acids eaten in crystalline form will be absorbed directly into the bloodstream. Your body can only use so much protein and any excess is used for energy or stored as fat. Your body uses protein to build and repair lean tissue (muscles and organs).

Weight lifting will increase muscle size and the average US diet and the RDA contains enough protein (females 50 gm and males 63 gm per day) to promote an increase in muscle mass. Some weightlifters talk about lifting breaking down their muscles. Any movement of protein out of muscles will go into the blood pool of amino acids that are available to all lean tissue. Research has shown that the uptake of amino acids improves in weightlifters during recovery after exercise.

A healthy person does not lose significant protein other than through hair and nails. So the protein and amino acids you eat stay in your body.