Almost 30 years ago, a gaseous element produced by the body was scientifically identified that relaxes vascular muscles, dilates blood vessels, and consequently increases blood flow and oxygenation. Since then, more than 30.000 scientific articles have been published recognizing the fundamental role of Nitric Oxide in vasodilation and cellular communication [1].
What is Nitric Oxide?
Nitric Oxide (NO) or Nitrogen Monoxide is a gas that can be naturally produced by the body through specific enzymes, called NO-synthase, starting from the amino acid Arginine.
Benefits of Nitric Oxide
The vasodilating effect of nitric oxide is of utmost importance for athletes - especially bodybuilders - since an increase in the supply of oxygen and nutrients to the muscles results in the possibility of training longer and more effectively.
During physical activity, cardiac output increases and blood flow redistributes to the benefit of muscle fibers. As you train, your muscles deplete their oxygen reserves. In the absence of oxygen, the body begins to produce lactic acid, which will cause muscle fatigue, to the point that we will have to finish the workout.
Nitric oxide reduces the amount of lactic acid produced during training, lengthening the time of muscle exhaustion. In addition, by accelerating the supply of oxygen and nutrients to stressed muscles, nitric oxide improves exercise capacity and sports performance.
Finally, the ability of nitric oxide to accelerate the removal of ammonia generated as waste during physical exercise, and to increase the absorption of glucose by cells are documented [3].
Nitric Oxide Supplements
The main components of supplements aimed at increasing the natural production of nitric oxide are Arginine and Citrulline. Both of these amino acids are known as precursors of nitric oxide, and their integration induces an increase in the level of nitric oxide in the blood.
Research highlights the role of arginine in reducing blood levels of ammonia and lactic acid produced during exercise [4], extending the time it takes until muscle failure. Taken together with Glutamine and BCAAs, arginine improves training efficiency by increasing the oxygen carrying capacity of the blood [5].
For bodybuilders, one of the most important effects of supplementing with arginine is its ability to stimulate the production of growth hormone (GH). Research shows that resting GH levels increase when L-Arginine is combined with exercise [6,7]. This is mainly due to the ability of arginine to suppress the secretion of somatostatin: a hormone that instead inhibits the production of GH [8]. As is well known, growth hormone stimulates the growth of cells and tissues, and is therefore essential for the increase of muscle mass.
It is therefore clear that the benefits of arginine go far beyond the simple ability to promote the synthesis of nitric oxide. As the aforementioned studies show, arginine has a direct effect on muscle growth.
Citrulline - another amino acid - has a higher absorption rate than arginine, and is therefore capable of efficiently restoring nitric oxide production. It is particularly useful when the body has limited availability of arginine [9].
Conclusion
It is now clear the mechanism according to which nitric oxide supplements are useful to athletes and bodybuilders: these supplements favor vasodilation and therefore the supply of precious nutrients to the muscle cells, consequently increasing sports performance. The 'pump' effect of these supplements is a sensation highly appreciated by those who frequent gyms regularly.
Arginine and Citrulline are two ingredients with proven efficacy that promote the increase in the production of nitric oxide. They can also have a direct influence on muscle growth in some cases. Highly bioavailable forms of these two amino acids are Citrulline Malate and Arginine Alpha Ketoglutarate.
References
[1] – British Journal of Pharmacology. 2006 Jan;147 Suppl 1:S193-201 [2] – Journal of Cardiovascular Pharmacology. 1999 Dec;34(6):879-86 [3] – Molecular and Cellular Biochemistry. 2004 Aug;263(1-2):29-34 [4] – International Journal of Sports Medicine. 2002 Aug;23(6):403-7 [5] – Journal of Nutrition. 2006 Feb;136(2):538S-543S [6] – Current Opinion in Clinical Nutrition and Metabolic Care. 2008 Jan;11(1):50-4 [7] – Journal of Strength & Conditioning Research. 2010 Apr;24(4):1082-90 [8] – Journal of Clinical Endocrinology and Metabolism. 1988 Dec;67(6):1186-9 [9] – Journal of Parenteral and Enteral Nutrition. 2008 Jul-Aug;32(4):377-83
