For strength athletes, bodybuilders, and everyday fitness enthusiasts alike: nitric oxide has entered the chat. What is nitric oxide? The simple answer is that it’s a gas that already exists in your body, and it may affect important functions — including blood flow.
Research and science over the last two decades point to a lot of health benefits of nitric oxide for athletes and non-athletes. Since this gas impacts your blood flow, it’s been linked to muscle gain and reduced soreness after working out — both crucial aspects of your training. Not to mention, this gas can also boost brain health and help lower your blood pressure.
You can increase your nitric oxide levels naturally and through supplements. But what does nitric oxide do to your body, exactly? If you’re looking to learn about nitric oxide for working out and other health-related nitric oxide uses, you’ve come to the right place.
Editor’s Note: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. When starting a new training regimen and/or diet, it is always a good idea to consult with a trusted medical professional. We are not a medical resource. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. They are not substitutes for consulting a qualified medical professional.
What Is Nitric Oxide?
What Does Nitric Oxide Do?
Nitric oxide suppresses cell inflammation and adhesion, limits blood vessel constriction, and promotes new vessel formation. (2) This widening of the blood vessels helps to increase vasodilation — otherwise known as blood flow. This has been shown to help to lower blood pressure and improve brain health, as well. (3)(4)
The nitric oxide effect of increasing blood flow led scientists to research the link between nitric oxide and exercise since blood flow is critical to training and hypertrophy. Here’s what happens in the body to create nitric oxide, and how you can harness that power to boost your training.
Nitric Oxide in the Body
Endogenous, or naturally occurring, nitric oxide is formed in the body from the precursors L-arginine (an essential amino acid) and nitrate. L-citrulline, a non-essential amino acid, is a precursor for L-arginine. (5) You might know these useful amino acids from the muscle-building supplements that you pop into your pre-workout.
If you’re devoted to the nutrition side of muscle-building, you may already pay attention to amino acids. L-arginine and L-citrulline, along with 18 other amino acids, make up muscle protein. Amino acids are vital to muscle protein synthesis — hence why they keep showing up in bodybuilding supplements. (6)
Nitric Oxide Food Sources
Since nitric oxide is a gas that’s created in your body, you can’t take nitric oxide. But you can help increase levels by ingesting the necessary precursors — nitrate, L-arginine, and L-citrulline. You can get a natural nitric oxide booster through whole foods and beverages. You can also take supplements to increase nitric oxide because they contain these amino acids.
Below are some natural sources of nitrates, L-arginine, and L-citrulline to increase and encourage nitric oxide production in your body.
- Beetroot (7)
- Kale, spinach, and other leafy greens (8)
- Strawberries, bananas, watermelon (9)
- Seafood, meat, and soy
- Nuts and seeds
- Dark chocolate
- Coffee and tea
Nitric Oxide Supplements
Nitric oxide supplements come in many different forms. You can get nitric oxide powder to mix into your smoothies. On the market, you will also find nitric oxide pills, nitric oxide tablets, and nitric oxide vitamins.
Remember that you cannot actually take nitric oxide directly into your body. You can always check the ingredients in nitric oxide supplements to ensure that they include L-citrulline and L-arginine, the amino acids needed to help boost nitric oxide in your body. (5)
Potential Benefits of Nitric Oxide
Nitric oxide in the body helps to widen blood vessels. It’s been shown to have a notable role in controlling vasodilation, blood rate, and mitochondrial respiration. (10) These processes may have a direct impact on exercise performance, blood pressure, and cardiovascular and brain health.
Let’s take a deeper dive into each of these potential nitric oxide benefits to find out more.
May Improve Exercise Performance
But exactly what does nitric oxide do for working out? Nitric oxide helps to increase blood flow, and blood flow sends nutrients and oxygen to your muscles during strength training. In turn, this can help you get the most out of your program.
May Aid In Hypertrophy
What is nitric oxide used for in bodybuilding? All that healthy blood flow and vascularity may help you train longer and harder. This can have a net positive effect on hypertrophy training in the long run.
When bodybuilders are grinding out those slow, eccentric sets of biceps curls, the increased blood flow may help keep their muscles swelling through the end of their session.
However, this is a theory that hasn’t been fully proven. One study of the effect of citrulline supplements on upper-body resistance exercise on resistance-trained cisgender men failed to directly connect the supplementation to hypertrophy. (13)
The science still holds that blood flow delivery to your muscles is essential during exercise. (14) But, whether or not nitric oxide for muscle growth is a direct effect remains part of a larger picture of your training over time.
May Decrease Muscle Soreness
One of the other benefits of nitric oxide supplements is recovery.
With training often comes delayed onset muscle soreness (DOMS), and nitric oxide may help to decrease it. Studies have shown mixed results, and more research is needed. However, a 2020 study investigated the effect of nitric oxide precursor ingredients with other nutrients on the ability to increase nitric oxide levels and recovery after acute exercise. (15)
The study showed that taking the nitric oxide supplement — in addition to other nutrition and training strategies — improved the recovery of the athletes by accelerating lactate excretion from their bodies. (15) The study concludes that nitric oxide can have a positive effect on exercise performance and recovery. (15)
It’s not a direct link between nitric oxide supplements and decreased DOMs. Still, including nitric oxide supplements with other training, nutrition, and recovery practices can help clear your blood of lactic acid — which is often linked to post-exercise soreness.
May Lower Blood Pressure
Aside from your skeletal muscles, nitric oxide has a major effect on another muscle — your heart. The way that nitric oxide works in your body causes it to lower your blood pressure.
After it’s produced, nitric oxide diffuses into smooth muscles and causes them to relax. This results in vasodilation, which reduces systolic blood pressure while increasing blood flow and oxygen delivery. (16) A study showed that a single dose of a nitric oxide supplement significantly decreased both systolic and diastolic blood pressure after 20 and 60 minutes. (16)
Doctors will often prescribe nitric oxide supplements to folks with hypertension. If you’re wondering if you can take nitric oxide with high blood pressure, it’s always best to consult with your physician.
May Protect Cardiovascular Health
Nitric oxide is said to be integral to regulating blood pressure and maintaining a healthy cardiovascular system. Nitric oxide deficiency is associated with the development of hypertension and other forms of cardiovascular (CV) disease. (16) It plays an important role in the prevention of the onset and progression of CV disease. (17)
Atherosclerosis is one of the main underlying conditions that cause CV diseases, and it’s associated with endothelial dysfunction — or constricted blood vessels. (17) Since nitric oxide widens blood vessels, it may help prevent these conditions.
May Boost Brain Health
Nitric oxide improves blood flow to your skeletal muscles when working out, your heart for overall cardiovascular health, and one more major organ — your brain. Nitric oxide is a neurotransmitter and has been found to induce cognitive behavior in experiments on animals. (4)
A study found that L-arginine (a precursor for nitric oxide) may play a key role in the treatment of age-related degenerative diseases including Alzheimer’s. It also may be effective at preventing cognitive disorders caused by epilepsy and diabetes. (4)
Nitric Oxide Myths
There’s plenty of misinformation about what nitric oxide is and what it does. Let’s take a look at some popular myths.
Myth: Nitric Oxide Is a Drug
Nitric oxide is often confused with nitrous oxide, or the “laughing gas” you might get at the dentist or for other surgeries. It is not the same thing.
While they’re both chemical compounds made of nitrogen and oxygen, they have different numbers of nitrogen atoms. This subtle but significant difference gives the compounds vastly different chemical properties and impacts on the body.
Myth: Nitric Oxide Is a Good Pre-Workout
Since nitric oxide may improve exercise performance, athletes may wonder: is nitric oxide a good pre-workout? Remember that you can’t actually take nitric oxide. That said, many pre-workout supplements do include precursors to nitric oxide, including L-citrulline and L-arginine.
If you’re looking for increased feelings of energy and reduced fatigue from your pre-workout, nitric oxide supplements alone probably won’t deliver. But you can reap the potential nitric oxide supplement benefits by choosing a pre-workout that includes those amino acids as precursors.
Myth: Nitric Oxide Is Safe
Whether or not nitric oxide is “safe” will differ for each individual, and you should always consult with your physician before trying something new. Can nitric oxide be harmful? It depends. It can interact with certain medications, and it’s sometimes not recommended for folks with kidney disease.
Additionally, nitric oxide supplements, like all dietary supplements, do not need to be regulated by the FDA (Food and Drug Administration) to be sold.
Potential Drawbacks of Nitric Oxide
Although nitric oxide has potential benefits, it has potential drawbacks as well.
Nitric Oxide Supplement Side Effects
Nitric oxide supplements, like any supplements, may cause side effects. Some users report experiencing blurry vision, dizziness, fainting, slow heartbeat, diarrhea, stomach pain, nausea, and headache.
Could Lower Blood Pressure Too Much
Although nitric oxide’s ability to lower blood pressure is a potential benefit for folks with high blood pressure, it’s a potential drawback for folks who have lower blood pressure. It’s not recommended for people with hypotension (low blood pressure) because it’s possible to lower your blood pressure too much.
Not Enough Research
Some research on nitric oxide remains conflicting or inconclusive. Other research remains focused on a specific population — cisgender men who are experienced lifters.
Expanding research on nitric oxide to focus on populations like trans and nonbinary people, inexperienced lifters, cisgender women, and people of color can provide more insights into how supplements impact the body.
It’s Not Nitrous
While you may giggle when you get nitrous gas at the dentist, it’s not the same as the naturally occurring gas, nitric oxide. You can boost nitric oxide levels in your body by adding in more nitrates, L-arginine, and L-citrulline through your diet or supplements.
Nitric oxide widens blood vessels and increases blood flow throughout your body to your skeletal muscles, heart, and brain. This can translate into improved exercise performance and recovery, lower blood pressure, and increased cardiovascular and brain health. But we still need more research on more diverse populations.
This research will help flesh out the direct link between nitric oxide supplements and the benefits they may provide. With that research, your training and supplement game could really take off.
- Bruckdorfer R. The basics about nitric oxide. Mol Aspects Med. 2005 Feb-Apr;26(1-2):3-31.
- Ghimire K, Altmann HM, Straub AC, Isenberg JS. Nitric oxide: what’s new to NO? Am J Physiol Cell Physiol. 2017 Mar 1;312(3):C254-C262.
- Kapil V, Khambata RS, Robertson A, Caulfield MJ, Ahluwalia A. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension. 2015 Feb;65(2):320-7.
- Paul V, Ekambaram P. Involvement of nitric oxide in learning & memory processes. Indian J Med Res. 2011 May;133(5):471-8.
- Gonzalez AM, Townsend JR, Pinzone AG, Hoffman JR. Supplementation with Nitric Oxide Precursors for Strength Performance: A Review of the Current Literature. Nutrients. 2023 Jan 28;15(3):660.
- Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017 Aug 22;14:30.
- Dos Santos Baião D, Vieira Teixeira da Silva D, Margaret Flosi Paschoalin V. A Narrative Review on Dietary Strategies to Provide Nitric Oxide as a Non-Drug Cardiovascular Disease Therapy: Beetroot Formulations-A Smart Nutritional Intervention. Foods. 2021 Apr 15;10(4):859.
- Kurtz TW, DiCarlo SE, Pravenec M, Morris RC. Functional foods for augmenting nitric oxide activity and reducing the risk for salt-induced hypertension and cardiovascular disease in Japan. J Cardiol. 2018 Jul;72(1):42-49.
- Kobayashi J, Ohtake K, Uchida H. NO-Rich Diet for Lifestyle-Related Diseases. Nutrients. 2015 Jun 17;7(6):4911-37.
- Oral O. Nitric oxide and its role in exercise physiology. J Sports Med Phys Fitness. 2021 Sep;61(9):1208-1211.
- Wylie LJ, Mohr M, Krustrup P, Jackman SR, Ermιdis G, Kelly J, Black MI, Bailey SJ, Vanhatalo A, Jones AM. Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance. Eur J Appl Physiol. 2013 Jul;113(7):1673-84.
- Lansley KE, Winyard PG, Fulford J, Vanhatalo A, Bailey SJ, Blackwell JR, DiMenna FJ, Gilchrist M, Benjamin N, Jones AM. Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study. J Appl Physiol (1985). 2011 Mar;110(3):591-600.
- Gonzalez AM, Spitz RW, Ghigiarelli JJ, Sell KM, Mangine GT. Acute Effect of Citrulline Malate Supplementation on Upper-Body Resistance Exercise Performance in Recreationally Resistance-Trained Men. J Strength Cond Res. 2018 Nov;32(11):3088-3094.
- Trinity JD, Broxterman RM, Richardson RS. Regulation of exercise blood flow: Role of free radicals. Free Radic Biol Med. 2016 Sep;98:90-102.
- Mor A, Yılmaz AK, Acar K, Birinci MC, Ipekoglu G. Does Nitric Oxide Intake Affect Post-Exercise Recovery in Athletes? A Study on Cocoa, Caffeine and Nitric Oxide Supplement: Effect of Nitric Oxide Intake in Athletes. Progr Nutr [Internet]. 2020 Sep. 30
- Houston M, Hays L. Acute effects of an oral nitric oxide supplement on blood pressure, endothelial function, and vascular compliance in hypertensive patients. J Clin Hypertens (Greenwich). 2014 Jul;16(7):524-9.
- Naseem KM. The role of nitric oxide in cardiovascular diseases. Mol Aspects Med. 2005 Feb-Apr;26(1-2):33-65.
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