In search of the next best thing (or just supplement variety), many athletes ask me about Nitric Oxide products. Anecdotally, many report a power boost from taking them. But the research is equivocal, at best.
Nitric oxide is short lived in the body, 6-10 seconds. It’s rate limiting substrate is believed to be arginine (turn over any NO product and you’ll see l-arginine or AAKG). In the body, NO relaxes smooth blood vessels which leads to greater blood flow in certain areas of the body. So the theory goes like this – increase NO production = increased blood flow = greater power which leads to training adaptations over time.
One of better studies on NO was done in 2006 by my friend and colleague Bill Campbell (now at Univ S FL). He gave resistance trained males 12 grams of AAKG for 8 weeks. At the end of this time period the subjects showed significant increases in bench press and anaerobic power but no change in lean tissue mass.
And last week at the NSCA conference (www.nsca-lift.org) in Vegas, study results for GNC’s Amplified Maxertion NO were presented. Subjects pedaled to exhaustion on a cycle ergometer pre supplementation and after 4 weeks of 1.5 and 3 grams of arginine. After 4 weeks both groups improved performance at fatigue. The application for this – endurance exercise. Hopefully the full study will be published soon.