Arginine is an amino acid that is involved in many different processes. It is most famous for its potential to enhance nitric oxide synthesis and increase “muscle pumps”.
The body can synthesize Arginine so it is not considered one of the essential amino acids. However, athletes and bodybuilders may need supplementation to meet increased demands of training. Many animal products such as meat and dairy contain Arginine, and also plant sources such as wheat, nuts, and seeds.
Nitric oxide is a strong vasodilator that occurs in the body. It is causes what bodybuilders refer to as “the pump”, which is when muscles look larger and feel harder through increased blood flow. This increased blood flow may also help deliver additional nutrients and increase endurance. Since Arginine is a vital precursor of nitric oxide synthesis, supplementation may help to increase the pump effect.
Arginine Benefits for Growth Hormone
Growth hormone boosters often contain Arginine as a key ingredient. In combination with ornithine (Williams, 1999) or lysine (Isidori et al, 1981) Arginine has been shown to increase the secretion of human growth hormone in test subjects. This effect appears to be more apparent in subjects with lower baseline levels, such as older athletes or beginner athletes. Young experienced bodybuilders may not benefit so much as their levels of growth hormone are already elevated.
Arginine Benefits for Strength & Endurance
Individuals who use arginine together with ornithine have been shown to experience an increase in strength, lean mass, and recovery (Elam et al, 1989). Additional studies looking at arginine found that an arginine supplement that also contained vitamins C and E was able to significantly increase cyclists’ endurance capacity(Chen et al, 2010). Such benefits might have been a result of an increase in nitric oxide production.
An increase in nitric oxide synthesis which leads to increased blood flow may also be beneficial for delivering anabolic nutrients such as other amino acids that are needed for muscle growth (Paddon-Jones et al, 2004).
Arginine Benefits for Erectile Dysfunction
Aside from exercise performance, nitric oxide can also play a role in penile erection. For this reason, it has been suggested that arginine could also be a viable treatment for erectile dysfunction. Research has shown improvements in erectile dysfunction when arginine was supplemented, especially in combination with pycnogenols (MacKay, 2004).
Arginine Negatives & Side Effects
One potential problem with arginine is that it has quite a low absorption rate as it is not very stable once it enters the digestive system. The absorption could be as low as 38%, which means arginine may not actually be the best way to increase nitric oxide synthesis. Instead, it has been found that the amino acid citrulline, is more effective in raising blood arginine levels than arginine itself (Schwedhelm et al, 2008). Alternatively, absorption may be increased through binding arginine with other compounds such as alpha-ketogluarate.
The safety of arginine is not commonly an issue. It is a common amino acid found in the body and any excess can be easily eliminated from the body. It has been estimated that a 70 kg man is able to tolerate up to 20 g arginine per day over an extended period of time (Wu et al, 2007). However, higher levels than this may lead to stomach upsets.
Arginine Recommend Doses and Ingredient Timing
Doses as low as 1 or 2 grams of Arginine may be able to increase exercise performance when taken 30-60minutes before exercise. Athletes and bodybuilders can take another dose before bed on an empty stomach. This dose before bed may be beneficial for increasing growth hormone levels.
Arginine supplements come in three forms. Pure arginine is often used before workouts. Protein and amino acid blends also tend to contain arginine, either naturally occurring, or additionally added. Arginine and its derivatives are also common additions to pre workout supplements.
An example of a product containing Arginine is Musclepharm’s latest pump supplement VasoSport. It contains Arginine bonded with Silicon as Nitrosigine, along with Citrulline Malate and Agmatine Sulfate. Citrulline Malate is an amino acid that converts to Arginine to increase nitric oxide synthesis, and Agmatine Sulfate inhibits nitric oxide synthase which is the enzyme that breaks down Nitric oxide meaning the pump effect will last for longer. Agmatine Sulfate is also an effective vasodilator so directly stimulates nitric oxide synthesis.
There are many different ways to stack Arginine depending on your goal. Athletes and bodybuilders can stack Arginine with Lysine for increased growth hormones, or with citrulline fo increased nitric oxide synthesis and muscle pumps.