Citrulline supplements are often suggested for athletes and bodybuilders working to improve performance and boost energy. Citrulline helps remove toxic ammonia from muscles, which is one way it may improve muscle activity. Citrulline is also converted into arginine, which triggers the release of growth hormone and produces nitric oxide. Nitric oxide relaxes muscles and improves blood flow.
Compared to L-arginine, L-citrulline may be an alternative approach at nitric oxide induced increases in muscle blood flow that may provide an anabolic approach to exercise training. Nitric Oxide (NO) is a key molecular and cellular messenger in the body that, among other biological processes, is used to increase blood flow in the body through dilation of blood vessels. Arginine, a precursor to NO, has long been the standard means of triggering increased production of NO in the body.
The new research suggests citrulline may be a more effective way of elevating arginine levels and NO in the body. L-citrulline, often referred to as simply citrulline, is an amino acid first isolated in the 1930’s from watermelon. Your body produces citrulline, so it isn’t considered an essential amino acid that you must get from your diet. L-Citrulline is used as a sports performance and cardiovascular health supplement.
Citrulline may improve exercise performance and reduce post-workout muscle soreness, according to a study published in the “Journal of Strength and Conditioning Research” in 2010. In the study, 41 men performed sets of barbell bench presses. During some training sessions they took citrulline malate, and during others they took a placebo pill.
When they took citrulline malate, they achieved 53 percent more repetitions and a 40 percent decrease in muscle soreness in the days following training. A 2015 study published in the same journal, divided 12 men with advanced resistance training into two groups. The group taking citrulline malate finished significantly more repetitions of lower body resistance exercises than the non-supplement group.
L-citrulline is also used to alleviate erectile dysfunction caused by high blood pressure. A short-term citrulline supplementation could functionally improve atrial stiffness in humans by increasing vascular relaxation and increasing blood flow to the body.
A recent study suggests that L-citrulline can do more than just pump up your muscle in the gym, but it may be good in the bedroom as well. A study titled, Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction, published in Urology suggests that L-citrulline can also enhance virility. An interesting statistic is that about 30–40% of erectile dysfunction (ED) patients are non-responders to phosphodiesterase type-5 (PDE-5) inhibitor therapy.