Arginine is an amino acid that increases your body's production of nitric oxide, which is thought to increase blood flow to the muscles for a greater exchange of nutrients. It's a popular addition to many supplements thought to increase performance. "Even though there's a tiny bit of supportive research for arginine's increasing performance, it's not overwhelmingly positive," says Chad M. Kerksick, ., assistant professor of exercise physiology at the University of Oklahoma. He took part in a study at Baylor University, in Texas, that found a small increase in bench-press strength with arginine. But a 2006 study published in the Journal of the American Medical Association found that taking a daily supplement with 9 grams of arginine may cause heart attack or even death in men with known—and unknown—heart disease. That study was forced to end early.
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.     
It's not difficult, hard, or complicated...it's actually really, really easy to do!
But strangely enough, some guys just don't get it.
Which brings me directly to disclaimer number 2 (sorry folks, but this has to be done).
If for some reason you do not understand the concept above, or are not willing to do it, please leave this page now.
The LAST thing I want is for you to order one supplement, take it 36 days in a row, then email me, complaining that it doesn't work.
I'm tired of getting emails like this!
If you can't or will not cycle, move on please, there's nothing to see here.