Do Nitric Oxide Supplements Work?

Do Nitric Oxide Supplements Work?

Nitric Oxide is a gas formed in the body by the breakdown of L-Arginine to L-Citrulline through an enzyme group called Nitric Oxide Synthase (NOS). Although nitric oxide is used for many purposes, it’s ability to increase blood flow will be discussed in this article.

In general supplement companies claim that nitric oxide supplements can:

Increase recovery post workout
Increase resistance to muscular fatigue
Increase muscular work output

Many supplements such as BSN NO Xplode and Gaspari SuperPump have seen a rise in popularity over recent years, but do these supplements work?

These three claims are largely based on the assumption that an increase in blood flow to muscle tissue will enable users to experience the claims that supplement companies put forward. Obviously there are many other variable factors that can influence your muscle mass growth and strength gains for example you general diet and training. So the claim is that if your diet and training are in place, taking a nitric oxide supplement will enable your body to build more muscle mass that the same diet and training regime without the nitric oxide supplementation.

There is absolutely no doubt that nitric oxide supplements increase blood flow. Just ask anyone how has taken a nitric oxide supplement and they will tell you blood flow is substantially increased. But does this blood flow actually produce the results that are claimed? Or is it mostly a mental advantage from feeling the pump!

VasodilationVasodilation is the process of a relaxation of blood vessels, allowing them to carry more blood to and from working muscle tissue. Vasodilation (to high levels) is triggered by the onset of exercise as the need for oxygen and nutrients is heightened during this time. The process of vasodilation is highly influenced by nitric oxide.

High levels of nitric oxide aid in the conversion of an enzyme (GTP) into another (cGMP) which serves as an important messenger to, amongst others, the relaxation of smooth vascular muscle in order to create vasodilatory effects. Therefore, if levels of nitric oxide are inhibited vasodilation may not occur to the extent that allows maximal performance.

In essence, vasodilation occurs when high levels of nutrients need to be transferred into muscles for energy production. Vasodilation itself is highly influenced, and limited by the amount of nitric oxide that is available as it has been observed that a limited production of nitric oxide can lead to vasoconstriction.

It can be suggested therefore that if we can enable the body to produce ample amounts of nitric oxide, proper levels of vasodilation can occur, enabling the body to transport ample amounts of nutrients to working muscle for maximal power output.

What Should Be Supplemented To Increase Nitric Oxide Levels?

Most nitric oxide supplements on the market currently use ingredients such as

L-Arginine
Arginine-alpha-ketoglutarateL-Citrulline
Citrulline Malate

As nitric oxide is produced by the conversion of l-arginine it can be supposed that supplementing with l-arginine will have an effect on NO levels. However the evidence as yet shows no correlation between oral arginine supplementation and nitric oxide levels. Unfortunately l-arginine concentration does not directly affect the rate of nitric oxide production. Citrulline, the amino acid that l-arginine is converted into in the nitric oxide conversion process has actually be shown to have a greater effect of nitric oxide levels with oral supplementation. However these amino acids alone do not seem to have a direct effect on nitric oxide levels.

InsulinInsulin is an incredibly important hormone that allows nutrients, including glucose to be transported to muscle cells and has been shown to be a regulator in vasodilation and blood flow.

It is important to discuss insulin levels as it has been studied that the effects of insulin on vasodilation are dependent on insulin sensitivity i.e. how much insulin can be released when carbohydrates are ingested. These studies have concluded that nitric oxide production by insulin can decrease in people that are insulin ‘resistant’ rather than people that are sensitive to the effects of insulin release.

It can be extrapolated that a heightening in insulin levels can produce hyper vasodilation and in fact, this has been shown in resulting studies.

How Can Insulin Be Raised To Spark Vasodilation?In fact the products mentioned earlier that are used in many nitric oxide products do increase insulin sensitivity in the body, therefore they do increase vasodilation but through heightened levels of insulin rather than a direct effect on l-arginine conversion.

How Are Nitric Oxide Supplements Best Supplemented?Insulin has a linear relationship with the ingestion of carbohydrates; if large amounts of carbohydrates are eaten larger amounts of insulin are released. Therefore many powdered nitric oxide supplements will combine their ingredients with simple fast acting carbohydrates such as dextrose in order to increase vasodilation and ‘the pump’. These carbohydrates are shuttled to muscle literally forcing the carbohydrate into the cells and filling them up like a balloon creating a larger muscle mass.

Powdered products are usually taken pre-workout only as supplementation of simple sugars is not recommended at any other time. Nitric oxide pills do not contain the sugars and will produce a slower effect on vasodilation by increasing your insulin sensitivity. Therefore carbohydrate ingestion is recommended around your workout to allow for the greatest chance of vasodilation trough insulin use.

The ClaimsEarlier the three most common claims of the supplement companies were mentioned and in general it can be concluded that nitric oxide supplements can produce those results (obviously there are other factors that can influence this). If vasodilation occurs with an increased insulin response from supplementation of nitric oxide products it can enable users to gain better results from supplementation.