L-Arginine

What is it?
Arginine is a conditionally essential amino acid.  It’s an essential amino acid in infancy/early childhood, and under stress conditions where the body cannot manufacture sui   cient l-arginine to meet increased demand. Beyond its role in   protein synthesis, arginine is a precursor for a number of important metabolites, including  creatine and nitric oxide.  It is an important intermediate in the urea cycle, and can stimulate the secretion of growth hormone.


What is it supposed to do?
The current interest in arginine and related compounds such as arginine-alpha-ketoglutarate (AAKG) lies in its role in the production of nitric oxide.  NO is the new superstar molecule with researchers as it appears to play a
role directly or indirectly in almost every aspect of human physiology, such as the immune system, nervous system, circulatory system, and many others.
Arginine is a key component of the NO production pathway (arginine serves as the substrates for the nitric oxide synthase enzyme, which produces  citrulline and NO from arginine) which is essential for a cascade of reactions involved in vasodilation and cardiovascular function. Supplements containing arginine/AAKG are supposed to enhance the production of NO, and increase the “pump” you get during a hard workout in the gym.

Recommendations
From a health perspective, arginine and arginine alpha-ketoglutarate, may have some real  uses for people with high  cholesterol, coronary artery disease, ischemic (meaning a reduced blood l ow and oxygen delivery to tissues) and even men with erectile dysfunction. As for athletes, the jury is still out for either arginine or arginine alpha-ketoglutarate.

Bottom line,  I would not recommend them to athletes at this time for increasing either muscle mass or performance. For that use, they get a thumbs down.

References: Brinksbodybuilding, WIKIPEDIA