Why is citrulline malate so popular?
Over the last few years, citrulline malate has become an increasingly popular supplement, all but stealing the limelight of its predecessor l-arginine. In fact, you’d be hard-pressed to find a pre-workout or performance boosting product that doesn’t contain it.
What is L-citrulline
L-citrulline is a naturally occurring amino acid readily found in watermelons that are converted to arginine in the kidneys after ingestion. Citrulline malate plays a major role in the essential mechanism that produces nitric oxide, an important vasodilator required for regulating blood pressure. Because of this, it has been used in assisting the treatment of numerous ailments such as high blood pressure, diabetes, erectile dysfunction and heart disease.
What are the benefits of citrulline malate
As well as the numerous health and cardiovascular benefits, citrulline malate's role in boosting nitric oxide production can have huge benefits in training. The increased vasodilation that comes with a boost to nitric oxide production can greatly increase the blood flow to both organs and muscle cells. This has two immediate benefits when considering athletic performance.
- Firstly, it allows for more blood to enter the muscles, making them look fuller and larger, giving that ‘pumped’ sensation many weight trainers crave.
- Secondly, this increase in blood flow allows for a greater quantity of nutrients to be shuttled into the muscle cells, whilst simultaneously enhancing the removal of exercise-induced waste products, leading to a significant boost in performance.
It is for these reasons that citrulline malate is now a staple ingredient in many pre- or intra-workout performance boosting formulas.
Where is the proof?
A study published in 2011 in the "Journal of Nutritional Science and Vitaminology" reported that laboratory animals fed citrulline and subjected to intense exercise were able to perform longer and also had lower levels of blood ammonia and lactate, two waste compounds produced during exercise, when compared to a placebo group.
While you may argue that animal studies are not always indicative of human applications, another study published in the September 2010 issue of the "European Journal of Applied Physiology" found that male cyclists who supplemented with citrulline malate two hours before exercise showed blood markers indicating improved amino acid use by their tissues when compared to a control group. However, since these initial studies, multiple other human studies have shown that citrulline malate supplementation does attenuate fatigue both in regular gym users as well the individuals displaying fatigue problems during everyday life.
L-arginine vs citrulline malate?
Over the last few years, citrulline malate has steadily replaced l-arginine in most sports nutrition supplements and the reason for this is simple. Higher quantities of l-arginine can cause gastric discomfort and diarrhoea, whereas citrulline malate does not even in the largest dosages. More importantly, multiple studies have shown that citrulline malate supplementation is actually far more effective at increasing plasma arginine levels than l-arginine itself. This is the likely explanation as to why citrulline malate is more effective at boosting nitric oxide levels and thus providing a more notable effect when used in pre-workout and performance boosting formulas.