If you spend countless hours jacking steel and lifting heavy things at the gym, then chances are you’ve heard of nitric oxide boosters, or more commonly known as NO boosters. Several studies have shown that nitric oxide boosters can help improve athletic performance, increase workout volume, delay muscle fatigue, and improve recovery. But what exactly is nitric oxide? And which nitric oxide booster is the best? We’re going to deep dive into what exactly nitric oxide boosters are and which nitric oxide boosters are the best to help crush your workout.

In this article, you will learn the following about nitric oxide

• What Are Nitric Oxide (NO) Boosters?
• How Do Nitric Oxide (NO) Boosters Work?
• What Is The Best Nitric Oxide Booster?
• What Are The Benefits Of Nitric Oxide (NO) Boosters?

What Are Nitric Oxide (NO) Boosters?

Nitric oxide boosters are dietary supplements that are marketed to help support athletic performance, specifically by increasing strength, delaying muscle fatigue, promoting endurance, improving workout volume, and optimizing recovery [Basically, a magic bottle of gains.] Nitric oxide boosters are not actually made with nitric oxide, but rather foods high in nitrates, which promote the process of nitric oxide production, such as beets, kale, watermelon, leafy greens, and/or amino acids such as L-Arginine and L-Citrulline.

How Do Nitric Oxide Boosters Work? 

Nitric oxide is a gas that's main purpose is to promote vasodilation or increased blood flow.

NO is one of the most fundamental molecules of the body’s vasculature, regulating key signaling pathways and nutrient transport. NO is secreted by the endothelial cells and line the inner walls of your blood vessels, communicating to your smooth muscle cells to relax, through vasodilation. Consequently, nitric oxide widens blood vessels increasing blood flow and circulation without increasing blood pressure. Research has shown that nitric oxide is essential for overall health, especially cardiovascular health as it supports the transport of blood, oxygen, and nutrients to your body and muscle tissue efficiently and effectively.

What Is The Best Nitric Oxide Booster?

There are several dietary supplements that are marketed as, “Nitric Oxide Boosters.” However, with so many options, it can be confusing to know which NO booster provides the most benefit for improving overall athletic performance.  We’re going to break them down one by one according to the scientific research and find out what nitric oxide booster is the best.      

L-Arginine

L-Arginine is a conditionally essential amino acid and a precursor to nitric oxide. Conditionally essential meaning that at times your body cannot make sufficient amounts, to keep up with energy demands, therefore it must be consumed either from the foods in your diet, or through supplementation.

Several studies have investigated the effects of L-Arginine supplementation on nitric oxide synthesis, muscle protein synthesis, and exercise performance; however study results have been mixed.

In a double-blind randomized controlled study, published in the journal Applied Physiology, Nutrition, and Metabolism, fifteen males subjects supplemented 6g of L-arginine or a placebo to investigate the effects of arginine supplementation on strength, NO production, and recovery. The study found that while L-arginine increases muscle blood volume, arginine does not help promote increases in strength performance [R].

In another double-blind randomized controlled trial, published in the European Journal Of Nutrition, twenty physically active elderly women were randomly assigned to supplementing with 10g of L-arginine or placebo. Both groups had a total of three visits, in where they underwent ultrasound at rest and immediately before and after isokinetic strength and muscle performance tests. The results showed that there were no significant differences between arginine and placebo on muscle performance [R].

Yet, a systematic review in the Journal Sports Medicine, identified five acute studies that evaluated exercise performance while supplementing with L-Arginine. Three of the studies evaluated found that arginine supplementation promoted vasodilation, thus improving strength, power and muscular recovery through increased substrate utilization and metabolite removal, such as lactate and ammonia [R].

Therefore, studies show that L-arginine is effective as a nitric oxide booster, yet there are mixed results when used as an ergogenic aid, and enhancer on exercise performance.

L-Citrulline

L-Citrulline is an amino acid, that is a by-product or precursor of L-arginine. In fact, L-citrulline increases arginine levels more than supplementing with L-arginine alone. This is due to the poor bioavailability and uptake of arginine. In a study published in the Journal Of The International Society Of Sports Nutrition twenty two trained male participants consumed 2.4 g/day of L-citrulline or placebo orally for 7 days to evaluate cycling time trial performance. On Day 8 they took 2.4 g of L-citrulline or placebo 1 h before a 4-km cycling time trial. Time taken to complete the 4 km cycle, along with power output/VO2 ratio (PO/VO2), plasma nitrite and nitrate (NOx) and amino acid levels, and visual analog scale (VAS) scores, was evaluated.

The results showed that L-Citrulline supplementation significantly increased plasma L-arginine levels and reduced completion time by 1.5 % (p < 0.05) compared with placebo. Moreover, L-citrulline significantly improved subjective feelings of muscle fatigue and concentration immediately after exercise [R].

A comprehensive review published in the Journal Of Strength And Conditioning evaluated the effects of L-Citrulline supplementation on exercise performance through human clinical trials. The review concluded that several studies have reported that L-citrulline supplementation can enhance exercise performance and recovery [R].

Citrulline Malate 2:1

Unlike other NO boosters, Citrulline Malate is perhaps the most impressive when it comes to athletic performance benefits. Citrulline Malate is a combination of the amino acid L-Citrulline and malate, a derivative of Malic Acid. Citrulline is derived from watermelons and malate is derived from apples.

Endurance training as well as resistance training, impose a significant energy demand when it comes to aerobic and anaerobic function, power output, and strength. Studies suggest that Citrulline Malate works through several unique mechanisms of action, as opposed to other NO boosters, which can benefit nearly all aspects of performance such as strength, endurance, and recovery.

In addition to promoting the natural release of nitric oxide, citrulline malate

• Increases ATP Production [R]
• Increases phosphocreatine levels [R]
• Facilitates Muscle Protein Synthesis  [R]
• Enhances Amino Acid Utilization [R] 

A study published in the British Journal Of Sports Medicine, found that 6g of Citrulline Malate taken daily, reduced muscle fatigue, by producing a 34% increase in the rate of oxidative ATP production during exercise. The study also found a 20% increase in the rate of phosphocreatine recovery after exercise, indicating a larger contribution of oxidative ATP synthesis to energy production. [R] Thus, Citrulline Malate supplementation can help you fight muscle fatigue, due to the increase in ATP production and phosphocreatine release after exercise. When you’re competing at an elite level, generating more energy can provide a sustainable impact on your athletic performance. 

RELATED ARTICLE Citrulline Malate: 3 Clinically Proven Benefits Of Citrulline Malate And How It Can Improve Your Training

In another study, published in the Journal Of Strength and Conditioning Research, at the University of Córdoba, Spain 41 male participants performed two consecutive flat barbell bench-training sessions for a total of sixteen sets. 8g of Citrulline Malate were administered during one of the first two sets and placebo was administered for the third. The subjects' resistance was tested using the repetitions to fatigue test at 80% of their predetermined one rep max in the 8 sets of bench presses during the training session. The number of reps showed a significant increase from placebo treatment to treatment with Citrulline Malate from the third set achieving 52.92% more repetitions. The study also showed a 40% reduction in muscle soreness at 24 hours and 48 hours with a response rate greater than 90% with Citrulline Malate supplementation. [R] Again, this study proves that one of the greatest benefits of Citrulline Malate is reducing muscle fatigue, in addition to optimizing post-workout recovery.

RELATED ARTICLE 5 Ways Citrulline Malate Can Improve Your Athletic Performance

A systematic Cochrane review published in 2019, analyzed twelve studies with a total of 198 study participants, to examine the Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance. The results found that citrulline malate supplementation provides a significant benefit to high-level athletes as compared to placebo [R].

Beetroot Juice 

Beet juice has made a massive surge in the NO market. Research has shown that beet juice and nitrate supplementation, is one of the most promising nitric oxide boosters, which may produce positive ergogenic benefit and the ability to improve exercise performance.

In a randomized cross-over study, published in the Journal Medicine Science in Sports Exercise, nine athletic trained cyclists, 0.5L of beetroot juice or placebo two hours prior to the completion of a 4 and 16km time trial. The study concluded that beetroot juice supplementation increased plasma nitrate levels, producing higher power output at the same VO2 max [R]. A research group with a similar study design from the Netherlands produced similar results and showed an increase in power output and optimized VO2 in a group of twelve trained cyclists over a study period of six days [R].

What Are The Benefits Of Nitric Oxide Boosters?

The main benefit of any nitric oxide booster is obviously to increase and facilitate nitric oxide production. Through this release of NO, you'll be able to increase blood flow, oxygen, and nutrient transport to your muscles, which will, in turn, improve performance. Benefits of all nitric oxide supplements include

• Improve Recovery Time
• Increase Strength
• Fuel Endurance 
• Delay Muscle Fatigue 

However, studies indicate that the surmounting difference between Citrulline malate is that L-citrulline, Arginine, and Beet Juice alone does not directly affect aerobic ATP production. Malate which is an intermediate of the tricarboxylic acid cycle (TCA) or urea cycle affects aerobic ATP production through anaplerotic reactions [R]. Therefore, Citrulline Malate has added benefits such as

• Delayed Muscle Fatigue - Increases ATP Production [R]
• More Power - Increases phosphocreatine levels [R]
• Increased Strength - Facilitates Muscle Protein Synthesis  [R]
• Better Recovery - Enhances Amino Acid Utilization [R] 

Which Nitric Oxide (NO) Booster Should You Take? 

The most notable, and best overall ergogenic aid is Citrulline Malate. Most, if not all of the research on nitric oxide boosters, show mixed results. However, as compared to other NO boosters, Citrulline Malate shows the most promising performance benefits. Citrulline, Arginine, and Beetroot juice do provide more blood and oxygen transport by promoting the release of nitric oxide. However, studies indicate that L-Citrulline and L-Arginine alone does not directly affect aerobic ATP production. Malate which is an intermediate of the tricarboxylic acid cycle (TCA) or urea cycle affects aerobic ATP production through anaplerotic reactions [R].

Citrulline Malate is really an all in one super supplement.

The clinical evidence suggests that Citrulline Malate proves to be, not only a good nitric oxide booster for but the best no booster for endurance athletes. Through its ability to increase strength, enhance endurance, and optimize post-workout recovery and soreness, there's never been a better supplement to help in every aspect of your training. If you want to gain an athletic edge over your competition, lift heavier, clock faster times, and train harder with less muscle fatigue and soreness then you should absolutely add Citrulline Malate to your pre-workout regimen. By adding Citrulline Malate into your workout routine, you will get to your goals faster and achieve greater enhancements in overall performance. 

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