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Nitric Oxide (NO): Much More Than the Perfect Workout Booster

One of the most widely studied molecules of the past three decades – and unquestionably important from a bodybuilding standpoint –  is Nitric Oxide, or NO. Known within strength training and muscle building circles as an effective way to promote the coveted muscle ‘pump’ (engorgement of blood within working muscles). NO also serves to enhance nutrient and oxygen delivery to muscle tissue, regulates insulin secretion, increases muscle velocity and elevates power output. NO has, since it was first used in 1996, increasingly become a staple part of many a hard training athlete’s supplement regimen.


Nitric Oxide 101

Considered an important signaling molecule given the extent to which it regulates many of our most critical cellular and physiological processes – most notably for bodybuilders, blood flow, or hemodilation – NO is an essential ingredient in most good pre-workout formulations. Aside from its cell volumizing bodybuilding benefits, NO’s positive effects extend to immune system integrity, the regulation of cell death, and neurotransmission: respectively, NO may encourage good health, enhance the structural stability of our healthy cells and promote sounder nervous system functioning to improve physical and mental performance.


The NO Breakthrough

Originally termed Endothelium-Derived Relaxing Factor (EDRF) after scientists had first identified its blood vessel relaxant properties, and its role in influencing vascular tone, NO (at first assumed to be a protein like other signaling molecules) was discovered to be a highly reactive gas. It was subsequently named Nitric Oxide and has since had over 60,000 scientific papers published on it. In 1992, NO was named Molecule of the Year by the prestigious journal, Science. The pioneering work researchers’ Louis Ignarro, Robert Furchgott and Ferid Murad conducted on Nitric Oxide won them a Nobel Prize in 1998. However heavily studied and clinically proven a substance is, however, that does not necessarily correlate with its efficacy in real life situations. A noteworthy, publishable effect may be of a greater or lesser nature and its application may not have real world significance, or at best its usefulness may be debatable. Fortunately for hard training athletes, NO is the real deal. 


Prime the Pump to Build the Muscle


Nitric Oxide’s artery dilating properties increase blood flow to working muscles in response to NO production – ok, but how? This is how it works… The endothelium (the central layer of cells which comprise our arteries) releases NO in the presence of the enzyme Nitric Oxide Synthase (NOS), whereupon NO informs the smooth muscle cells of our artery walls to relax (they do so by dilating). As a result, blood pressure is driven down and blood flow is increased.


Whenever NO enters the bloodstream, blood flow improves. Scientists discovered that by increasing NO production beyond normal levels human performance may be significantly elevated. The typical effects of supplementally derived  NO include massive muscle pumps; improved power output; greater recovery between sets; and enhanced muscle growth (due in part to enhanced protein synthesis resulting from more protein being shuttled into muscle tissues via increased blood flow).


Arginine For the Win

Contrary to what their name may suggest, NO supplements do not contain any actual NO – in fact, the central ingredient in all NO products is the amino acid Arginine (or L-arginine), and more recently Citrulline Malate, a more efficient source of Arginine (nitric oxide itself is scientifically referred to as arginine-alpha-keto-glutarate, or AAKG). To manufacture NO, the body breaks down Arginine to set in motion the chain of events outlined above. Though no clear dosing guidelines have been established, it is important to assess your tolerance levels to determine the right NO supplement dosage for your individual needs. Follow label instructions and, if in doubt, consult your physician to determine the safest dosage for you.


Additional NO Benefits

NO may reduce the possibility of cardiovascular disease in those who exercise regularly. Whenever we work for an extended period, the endothelium of our cells releases NO so it may exert its vasodilation effects to improve blood flow. A major precipitating factor in the formation of atherosclerosis (a plugging, or occlusion of our arteries) is damage to the endothelium. Whenever NO is released it prevents red blood cells from clumping together (or aggregating) and attaching to the endothelium wall, thereby potentially minimizing the possibility of heart disease or stroke. As mentioned, vascular tone is also controlled through NO release; this also serves to keep the arteries clean and clear and our risk of heart disease down. Improved recovery between hard workouts is a further benefit of increased NO levels. Nutrient uptake into damaged muscles has been shown to facilitate the healing process and NO speeds the rate at which nutrients pass through the blood, en route to providing valuable sustenance to sore, depleted muscle fibers. This increased blood flow may also offset inflammation resulting from intensive training sessions and reduce the delayed onset muscle soreness (DOMS) that is felt after particularly grueling bouts with the iron. Nitric oxide has also been shown to enhance recovery from chronic stress by decreasing tissue breakdown as shown by lower urinary hydroxyproline (UH) levels. The harder we train the more we are at risk of succumbing to performance inhibiting muscular fatigue. By training in the 8-12 rep range (a standard hypertrophy training protocol) with maximally heavy weights we accumulate an abundance of lactic acid, a by-product of anaerobic metabolism and a major limiting factor when it comes to pushing our those extra reps and recovering between sets. By releasing more oxygen into our muscle tissues during training we may negate lactic acid build-up. By relaxing our largest blood vessels and allowing more blood to flow into our muscles, more oxygen is delivered and waste products (including lactic acid) are more efficiently removed.


Say Yes to NO

As we have discussed, increased blood levels of NO have been shown to improve human performance and in many ways may benefit the muscle hungry among us (although, as is the case for most things, more is not better – always follow dosing instructions as provided on packaging and labels). In addition, the primary precursor of NO, Arginine (and of course Citrulline Malate), has a number of additional benefits of its own, including improved healing times and natural increases in growth hormone (GH). So the next time you go looking for a pre-workout, remember the tenets of Blood Volume Training (BVT) and make sure you are appropriately dosing yourself with efficacious levels of NO enhancing ingredients.


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