L-Arginine Supplementation Research

l-arginine usage for rugby players 

Can L-Arginine supplementation impact rugby performance?

Below, you'll find links and references to detailed L-arginine supplementation research focusing on all the primary ingredients contained in No2 Max™. If you have comments or questions about this research, please contact our product team, who will be able to clarify.

Ingredients in No2 Max™


L-arginine is an amino acid commonly sold in supplement form and obtained naturally in the diet. L-arginine-rich foods include plant and animal proteins, such as dairy products, meat, poultry, fish, and nuts. Necessary for the production of protein, L-arginine also helps rid the body of ammonia (a waste product) and stimulates the release of insulin. L-arginine is used to make nitric oxide (a compound that relaxes the blood vessels). Although some studies suggest that L-arginine may benefit certain health conditions, other research shows that L-arginine may have harmful effects on some individuals.

Academic Research

Pre-exercise arginine supplementation increases time to exhaustion in elite male wrestlers

Time to exhaustion was longer with arginine supplementation(1386.8±69.8 s) compared to placebo (1313±90.8 s) (p < 0.05). These results suggest that L-arginine supplementation can have beneficial effects on exercise performance in elite male wrestlers but cannot explain the metabolic pathways which are responsible from these effects.

L-arginine supplementation protects exercise performance and structural integrity of muscle fibers after a single bout of eccentric exercise in rats

...our study indicates that L-Arginine supplementation prior to a single bout of eccentric exercise alleviates muscle fiber damage and preserves exercise performance capacity.

L-Arginine supplementation improves antioxidant defenses through L-arginine/nitric oxide pathways in exercised rats

The findings of this study improved our understanding of how l-Arg supplementation prevents elevations of reactive oxygen species and favorably enhances the antioxidant defense capacity during physical exercise.

Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients?

The ergogenic response of L-citrulline or L-arginine supplements depends on the training status of the subjects. Studies involving untrained or moderately healthy subjects showed that NO donors could improve tolerance to aerobic and anaerobic exercise. However, when highly-trained subjects were supplemented, no positive effect on performance was indicated.

Acute L-arginine supplementation reduces the O2 cost of moderate-intensity exercise and enhances high-intensity exercise tolerance

Plasma NO(2)(-) concentration was significantly greater in the Arginine than the PL group and systolic blood pressure was significantly reduced . The steady-state O(2) uptake (VO(2)) during moderate-intensity exercise was reduced by 7% in the Arginine group. During severe-intensity exercise, the Vo(2) slow component amplitude was reduced and the time to exhaustion was extended following consumption of Arg. In conclusion, similar to the effects of increased dietary NO(3)(-) intake, elevating NO bioavailability through dietary L-Arg supplementation reduced the O(2) cost of moderate-intensity exercise and blunted the VO(2) slow component and extended the time to exhaustion during severe-intensity exercise.

Effects of arginine-based supplements on the physical working capacity at the fatigue threshold

There were significant mean increases (PRE to POST) in PWCFT for the 1.5 g (22.4%) and 3.0 g (18.8%) supplement groups, but no change for the placebo group (-1.6%). These findings supported the use of arginine-based supplements, at the dosages examined in the present investigation, as an ergogenic aid for untrained individuals.

Effects of arginine supplementation on post-exercise metabolic responses

The results indicated that arginine supplementation during the exercise recovery period could increase glucose and insulin concentrations, and decrease FFA availability in the blood.


Arginine-ketoisocaproate (A-KIC) is an amino acid compound which can boost the effects of nitric oxide production. It also has anticatabolic properties which helps prevent muscle breakdown during strenuous exercise. It also plays a role in the production of energy and aids in the removal of ammonia during workouts.

Academic Research

Glycine-Arginine--Ketoisocaproic Acid Improves Performance of Repeated Cycling Sprints

These findings reinforce the notion that GAKIC supplementation may be a useful aid for strength-power athletes, similar to creatine supplementation. Unlike creatine, which requires approximately 5 d of loading to produce improvements in high-intensity work (14), GAKIC appears to impart an ergogenic effect within minutes of consumption. This presents an obvious advantage for GAKIC supplementation.


Ornithine alpha-ketoglutarate (OKG) is a salt formed of two molecules of ornithine and one molecule of alpha-ketoglutarate. Studies in the medical field have shown that ornithine alpha-ketoglutarate preserve muscle protein synthesis and spares nitrogen after elective surgery. Studies show that OKG generates more glutamine and arginine in the systemic circulation than when these substances are given separately. OKG is a salt formed by combining two molecules of the amino acid ornithine and one molecule of alpha-ketoglutarate.

Academic Research

The effect of L-ornithine hydrochloride ingestion on human growth hormone secretion after strength training

A change magnitude of serum growth hormone was significantly larger in the L-ornithine hydrochloride condition than in the placebo condition, and the effect size was also large. A significant interaction was found in serum ornithine and a multiple comparison test showed that it was greater in the L-ornithine hydrochloride condition. Serum growth hormone level after strength training increases by L-ornithine hydrochloride ingestion in untrained young males.

Amino Acids as GH Secretagogues

High doses of oral ornithine have successfully raised growth hormone levels in some studies. Bucci, et al, investigated the effect of 40, 100 and 170 mg/kg of oral L-ornithine HCl on 12 bodybuilders. Twenty-five percent of the subjects experienced significant increases in serum growth hormone levels at the two lower doses, while half the subjects showed an increase in growth hormone at the highest dose. Growth hormone rose, in some cases, up to four times the baseline level.


Alpha-ketoglutarate (α-Ketoglutarate or AKG) is a keto acid produced by de-amination of the amino acid, glutamate, and is a metabolic intermediate in the Citric Acid Cycle. Alpha-ketoglutarate is an important nitrogen transporter in biochemical pathways. The amino groups of amino acids are attached to alpha-ketoglutarate via transamination reactions, where it is then carried to the liver where the urea cycle takes place. In this way, the combination of L-glutamine and alpha-ketoglutarate help support healthy nitrogen metabolism and energy production.

Academic Research

Glutamine: A Potentially Useful Supplement for Athletes

Based on the available clinical evidence, we would speculate that glutamine has potential utility as a dietary supplement for athletes engaged in heavy exercise training.

L-Glutamine Supplementation: Effects on recovery from exercise

Participants in the Glu group increased time to exhaustion following 6 days of supplementation, and appeared to recover from exhaustive exercise earlier than the Pla group.


L-Citrulline is used as a sports performance and cardiovascular health supplement. L-Citrulline supplementation results in reduced fatigue and improved endurance for both aerobic and anaerobic prolonged exercise. There is not enough evidence to support the claim that L-citrulline supplementation improves power output during exercise. Supplementing L-citrulline also increases ornithine and arginine plasma content. This means L-citrulline supplementation improves the ammonia recycling process and nitric oxide metabolism.

Academic Research

l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans

These results suggest that EGb 761 prevented brain damage in OVX female mice by improving grip strength and neurological deficits, and the mechanism of action is not through HO1/Wnt but via blocking the extrinsic apoptotic pathway.