By Robert Schinetsky
Nitric oxide boosters are some of the most popular supplements on the market, and for good reason — everyone loves getting a sick muscle pump during training.
But, how do nitric oxide boosters work, and more importantly, what is nitric oxide, anyway?
What Is Nitric Oxide?
Nitric oxide is an important signaling molecule found throughout the body. It is composed of nitrogen (N) and oxygen (O) and serves a multitude of functions including: 
● Vasodilation (widening of blood vessels)
● Regulating cell life & death
● Immune system response
● Nutrient transport
Nitric oxide also plays a key role in cardiovascular health as it promotes healthy blood flow and proper endothelial function. And, it may also help protect against endothelial cell dysfunction as well as combat inflammation and oxidative stress.  
Unsurprisingly, since nitric oxide promotes greater blood flow throughout the body, it may also benefit athletes looking to take their performance to the next level.
How Do We Produce Nitric Oxide?
The human body has two separate and independent pathways by which it can produce nitric oxide:
● Arginine-Nitric Oxide Pathway
● Nitrate-Nitrite-Nitric Oxide Pathway
When we encounter or experience certain stimuli (such as intense physical exercise), our bodies activate one of three specific nitric oxide synthases (NOS).
FYI, synthases are the enzymes that catalyze the production of nitric oxide.
The three types of nitric oxide synthase you’ll find are: 
● eNOS: endothelial nitric oxide synthase — responsible for most of the NO produced in our blood vessels
● iNOS: inducible nitric oxide synthase — involved with immune defense and mediation of inflammation
● nNOS: neuronal nitric oxide synthase — expressed in specific neurons of the CNS
When it comes to booster performance and pumps, the form of nitric oxide we are most interested in is endothelial nitric oxide — the kind that affects blood flow.
Benefits of Nitric Oxide
Increased Blood Flow
This comes as no surprise, as we’ve mentioned it several times already in this article, but the most well-known benefit of increased nitric oxide production is greater blood flow.
Greater blood flow means that more oxygen and nutrients (glucose, amino acids, etc.) are delivered to working skeletal muscles during exercise, which supports energy production and may help you train longer and with greater intensity before succumbing to fatigue.
Another benefit of increased blood flow during exercise is more efficient clearance of metabolic waste products. As our muscles contract, various waste products (hydrogen ions, ADP, etc.) are created and slowly build up the longer are muscles are under tension. 
As more of the acidic ions accrue, the pH in our muscle drops, leading to the “burning sensation” we feel during high-rep sets and culminating in muscle fatigue. The more efficiently these waste products can be removed the longer you will be able to train before failure sets in.
Greater Mitochondrial Density & Efficiency
Mitochondria, as you might remember, are the mini “nuclear power plants” that reside within every cell of our body and are responsible for the production of ATP — the “cellular currency” of energy production.
Beyond energy production, mitochondria also play a role in various cellular signaling processes including cell growth, differentiation, and apoptosis.
Researchers have identified that in addition to boosting nitric oxide, intense exercise also increases mitochondrial density (the number of mitochondria) and efficiency. 
Basically, our cells can generate more ATP (due to the increased number of mitochondria) and they can produce it more efficiently, both of which lead to greater overall energy production and athletic performance.
Angiogenesis is the growth of blood vessels from the existing vasculature.
Earlier, we stated that one of the functions of nitric oxide is that of an intracellular signaling molecule.
When we exercise, endothelial cells lining our blood vessels release nitric oxide which causes vasodilation. This leads to an increase in blood flow and a decrease in blood pressure, both of which promote cardiovascular health.
But, nitric oxide also also instructs our bodies to form new capillaries (mini-branches) within the existing vascular network, which further enhances blood flow, nutrient, and oxygen delivery to working muscles.  
Enhances Glucose Uptake
Glucose is the preferred source of energy our muscles use during high-intensity exercise, and blood glucose and glycogen (the stored form of glucose) serve as important energy substrates during intense physical activity.
The volume, speed, and efficiency with which our muscles can access, utilize, and store glucose is a key factor in how well we perform during training, and fatigue during exercise often is typically linked with glycogen depletion.
Nitric oxide has been shown to mediate glucose uptake in skeletal muscle during exercise independent of blood flow or insulin!
Studies find that nitric oxide facilitates this increase in glucose uptake into skeletal muscle via intracellular signaling which culminates in up-regulation of glucose transporter-4 (GLUT4) translocation.   
In other words, nitric oxide helps increase energy usage and production during workouts, which promotes greater performance. It may also speed recovery due to the enhanced glucose uptake in skeletal muscle, which helps replenish glycogen that is depleted during exercise.
How to Boost Nitric Oxide
Now that you’ve got a better understanding of what nitric oxide is and how it supports your performance in the gym, you’re probably wondering how you can increase it.
Well, exercise, in and of itself, prompts an increase in nitric oxide levels. So, by merely getting in the gym and getting after it, you’re boosting endogenous nitric oxide production.
Diet can also help support increased nitric oxide production as certain vegetables (arugula, beet root, kale, etc) are rich in nitrates.
Increasing your intake of nitrate-rich vegetables boosts nitric oxide production via the nitrate-nitrite-nitric oxide pathway, promoting greater blood flow, decreased blood pressure, and heightened athletic performance!
You can also use supplements to help boost nitric oxide.
Nutrex has done the research and developed an arsenal of pre workout supplements that enhance nitric oxide production through both pathways in the body.
Niox is a full spectrum pump enhancing product consisting of Glycerine and NO3-T® to help support nutrient absorption and transportation for maximum muscle pump effects.
Citrulline is a non-essential amino acid that has been shown to increase plasma and tissue concentrations of arginine (the “fuel” for nitric oxide production) more effectively than L-arginine, leading to greater nitric oxide production.
There’s also Outlift Concentrate, which contains both sodium nitrate and betaine nitrate (as NO3-T®) to support NO production via the nitrate-nitrite-nitric oxide pathway.
To get the best of both nitric oxide pathways and maximize NO production, consider stacking one scoop of Outlift Concentrate with one scoop Outlift Stim-Free.
1. Blaise, G. A., Gauvin, D., Gangal, M., & Authier, S. (2005). Nitric oxide, cell signaling and cell death. Toxicology, 208(2), 177–192. https://doi.org/https://doi.org/10.1016/j.tox.2004.11.032
2. Furchgott RF, Zawadzki JV. The Obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980;288:373–376.
3. Zhao Y, Vanhoutte PM, Leung SW. Vascular nitric oxide: beyond eNOS. J Pharmacol Sci. 2015;129:83–94.
4. Förstermann U, Sessa WC. Nitric oxide synthases: regulation and function. Eur Heart J. 2012;33(7):829–837d. doi:10.1093/eurheartj/ehr304
5. Layzer, R. B. (1990). Muscle metabolism during fatigue and work. Bailliere’s Clinical Endocrinology and Metabolism, 4(3), 441–459.
6. Brown, G. C. (2007). Nitric oxide and mitochondria. Frontiers in Bioscience : A Journal and Virtual Library, 12, 1024–1033.
7. Morbidelli, L., Donnini, S., & Ziche, M. (2003). Role of nitric oxide in the modulation of angiogenesis. Current Pharmaceutical Design, 9(7), 521–530.
8. P., C. J., & W., L. D. (2002). Nitric Oxide and Angiogenesis. Circulation, 105(18), 2133–2135. https://doi.org/10.1161/01.CIR.0000014928.45119.73
9. Higaki Y, Hirshman MF, Fujii N, Goodyear LJ. Nitric oxide increases glucose uptake through a mechanism that is distinct from the insulin and contraction pathways in rat skeletal muscle. Diabetes. 2001;50(2):241-247.
10. McConell GK, Huynh NN, Lee-Young RS, Canny BJ, Wadley GD. l-Arginine infusion increases glucose clearance during prolonged exercise in humans. Am J Physiol Metab. 2006;290(1):E60-E66. doi:10.1152/ajpendo.00263.2005.
11. Hong, Y. H., Betik, A. C., & McConell, G. K. (2014). Role of nitric oxide in skeletal muscle glucose uptake during exercise. Experimental Physiology, 99(12), 1569–1573. https://doi.org/10.1113/expphysiol.2014.079202