NO is a potent vasodilator which means that it causes blood vessels to open up allowing more blood to pass through. This results in increased blood being delivered to your muscles resulting in swelling of the muscles known as "The Pump". This swelling not only looks impressive but also results in the same kind of stretching as Creatine, resulting in increased protein synthesis. Also, the increased blood flow means more oxygen and more nutrients flowing into muscles where they can be used to provide energy and support hypertrophy while more toxins and waste products are removed from the muscles.

Citrulline can be made from arginine as explained above, but it is also possible to make arginine from citrulline. Therefore, increasing citrulline creates an additional pool of arginine for the body to use as a precursor to NO (Nitric Oxide).

Everyone has heard about Nitric Oxide precursors and their effects on vasodilatation (opening of the veins and arteries to increase blood flow), but you may not have heard about how NO precursors like Arginine and its various forms along with things like Citrulline Malate and other potentiators of NO can greatly increase the chances of muscle cell differentiation.

Nitric Oxide is produced in the bloodstream as a mechanism of dilating blood vessels, but in the cell it is used to increase the transformation of satellite cells into mature muscle cells, this further increasing your ability to transform your genetic potential. Arginine is an amino acid that is often bound to a carrier or delivery molecule like malic acid, alpha-keto-glutarate or orotic acid to increase its potency and bioavailability. L-Citrulline is an amino acid that will further increase blood levels of Arginine and further increase your ability to make new muscle cells just waiting to be filled with protein.

The other interesting thing about NO is that it is released by muscles during a workout to help pump more blood into your working muscles. Using a combination of topical and systemic (full body) Arginine-AKG products can vastly increase the amount of NO released in your muscle tissue. That's why Arginine products have such a great reputation among bodybuilders for increasing size and vascularity. Another big benefit is that Arginine helps burn stored body fat by up regulating the use of fats for fuel. So Arginine has a double benefit of increasing size and strength while cutting fat.

An issue with NO products is that you shouldn't take them with high doses of caffeine and other stimulants that can naturally constrict the blood vessels, since you will be countering all of the benefits that NO production can bring. Also, take the Arginine oral products on an empty stomach and use the topical Arginine as a pre-workout warm up rub and then once again after the workout to keep the blood flowing to your freshly pumped muscles.