If asked to name amino-acid rich foods, most people wouldn’t say watermelon. After all, it’s a fruit, not a protein source.
You don’t have to eat watermelon to take advantage of citrulline’s benefits, though. Many supplements contain citrulline as a main ingredient, usually as citrulline malate, a more potent citrulline compound with additional benefits.
Here’s a closer look at what citrulline can do for you.
How Citrulline Malate Works to Boost Nitric Oxide in Your Body
But, the digestive enzyme arginase blocks arginine absorption. That means some arginine is excreted in urine before it ever stimulates nitric oxide production.
Luckily, scientists discovered citrulline absorbs much better than arginine. Consequently, many supplements contain citrulline instead of (or in addition to) arginine for creating nitric oxide.
Why worry about boosting nitric oxide? Athletes and bodybuilders utilize increased nitric oxide boosts to get their blood flowing better during exercise. Essentially, nitric oxide tells blood vessels to dilate. As blood vessels dilate, blood delivers nutrients and oxygen more efficiently to cells.
Because citrulline malate boosts nitric oxide, it’s sometimes included in male sexual enhancement supplements. As nitric oxide enhances blood flow, bigger and harder erections result.
Scientists directly tested citrulline’s effects on erectile function in a 2011 study. Twenty-four men aged 46 to 66 with mild erectile dysfunction took 1.5 grams citrulline daily for a month. Half these men returned to normal erectile function as measured on an erection hardness scale. Men who experienced this improvement felt very satisfied with the results.
What is “Malate”?
Like citrulline, malate comes from fruit. Also known as malic acid, malate gives apples, grapes, and other fruits their sour or tart flavor. Malate is so sour candy companies use it to intensify flavor of super-sour sweets.
Malate participates in the Krebs cycle, also known as the citric acid cycle. Cells use the Krebs cycle to generate energy from a compound called pyruvate. But, the Krebs cycle requires oxygen. Without oxygen, pyruvate becomes fatigue-inducing lactic acid.
However, since citrulline enhances blood flow by encouraging nitric oxide production, citrulline malate ensures cells have plenty of oxygen to go through the Krebs cycle. Consequently, the malate in citrulline malate enters the Krebs cycle, thereby promoting energy production and preventing lactic acid buildup. These effects are especially beneficial during exercise.
Research confirms malate’s role in the Krebs cycle is a major reason citrulline malate promotes decreases exercise fatigue. Scientists measured a 34% increase in ATP production attributable to citrulline malate supplements.
Effects of Citrulline Malate Consumption
Now that we’ve reviewed what each citrulline malate component contributes, it’s time for a brief examination of its overall effects. What effects will you notice during your weightlifting session when you take citrulline malate?
A 2010 study published in the Journal of Strength and Conditioning Research gives us a pretty good idea. In the study, men took 8 grams citrulline malate or placebo before doing several sets of barbell bench presses. The citrulline malate group performed nearly 53% more barbell repetitions than the placebo group during the two final sets. And, their muscle soreness was 40% less than the placebo group.
Based on this study, it’s clear citrulline malate improves not only workout capacity but also recovery time. When was the last time you worked out longer but felt better afterwards? Citrulline malate lets you achieve that.
Citrulline malate’s benefits are obvious. In fact, citrulline malate could be the secret to making every workout the best workout of your life.
-  Rimando, AM, and PM Perkins-Veazie. “Determination of citrulline in watermelon rind.” Journal of Chromatography. 1078.1-2 (2005): 196-200.
-  USDA National Nutrient Database for Standard Reference. “Nutrient data for 09326, Watermelon, raw”.
-  Rodrigues, Joey. “Citrulline Malate: The Next Big Thing?” BodyBuilding.com. 2004 Jun 10.
-  WebMD “L-Citrulline”.
-  Callis, A, B Magnan de Bornier, JJ Serrano, H Bellet, and R Saumade. “Activity of citrulline malate on acid-base balance and blood ammonia and amino acid levels. Study in the animal and in man.”. Arzneimittelforschung 41.6 (1991): 660-3.
-  Schwedhelm, E, R Maas, et al. “Pharmacokinetic and pharmacodynamics properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism.”. British Journal of Clinical Pharmacology. 65.1 (2008): 51-9.
-  Bezaitis, Athan. “How Nitric Oxide Maintains Health”. USC News. University of Southern California. 2009 Feb 18.
-  Cormio, L, M De Siati, et al. “Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction”. Urology. 77.1 (2011): 119-22.
-  “Malic Acid”. Bartek Ingredients.
-  Bendahan, D, JP Mattei, et al. “Citrulline/malate promotes aerobic energy production in human exercising muscle.”. British Journal of Sports Medicine.. 36.4 (2002): 282-9.
-  Perez-Guisada, J, and PM Jakeman. “Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness.” Journal of Strength and Conditioning Research. 24.5 (2010): 1215-22.