Whether your athletic interests are endurance based, strength based, or aesthetically based, one fact is certain— energy is something we all could use a little more of. Based on this (and some of the most recent scientific evidence), you may want to give citrulline malate a try.
Citrulline malate is formed by the chemical bonding of citrulline to malate. Supplement R&D teams have been interested in this compound for years due to its potential to increase muscle blood flow and ATP (energy) levels–thus, delaying fatigue, promoting increased workout intensity, and supporting faster recovery.
Citrulline was originally isolated from watermelon. However, it is produced in the body by the conversion of other amino acids and is considered to be non-essential. One means for citrulline production in the body is through the conversion of L-arginine to nitric oxide (NO, a potent vasodilator), whereby NO synthase (an enzyme) oxidizes L-arginine to form NO and citrulline. Interestingly though, when citrulline is taken as a supplement, the kidneys can covert some of it back to arginine, which boosts blood arginine levels better than taking arginine itself—which promotes even greater NO production and blood flow to working muscle. The end result???—– Increased oxygen and nutrient delivery, removal of metabolic byproducts, and incredible pumps. In terms of clearing metabolic byproducts, citrulline is also key player in the urea cycle, a biological pathway whereby we remove of toxic ammonia that can build up from heightened protein metabolism due to intense training.
The malate component of citrulline malate is found in many sour fruits (e.g., green apples and sour grapes) and it gives them their tartness. From a metabolic perspective, malate is an important intermediate in Kreb’s cycle that produces ATP (energy) during aerobic performances.
Numerous studies have shown that taking citrulline supplements (like L-citrulline or citrulline malate) promotes great performance benefits in athletes of all levels. In a recent study, published in the European Journal of Nutrition, researchers evaluated the performance benefits of an 8 g preworkout dose of citrulline malate on upper- and lower-body submaximal resistance exercise performance to exhaustion during bench press (at 80% 1RM) and leg press (at 80% 1RM) in trained female weightlifters. The authors concluded that taking 8 g of citrulline malate, 1-hour prior to exercise, increased the number of repetitions completed during bench press (3% increase) and during leg press (17% increase). Notably, when athletes took citrulline malate, their ratings of perceived exertion were significantly lower from set-to-set, especially during bench press exercise.
ACTION POINT: We generally suggest taking at least 6 g of L-citrulline or citrulline malate 30-60 min prior to exercise or sports performance. However, based on the findings in this study, female athletes may benefit by taking as much as 8 g of L-citrulline or citrulline malate prior to training. Females may benefit from a little more citrulline because their hormones promote greater NO production than their male counterparts. As always, start with a lower dose and build slowly to higher doses to assess tolerance.
Reference: Glenn JM, Gray M, Wethington LN, Stone MS, Stewart RW Jr, Moyen NE. Acute citrulline malate supplementation improves upper- and lower-body submaximal weightlifting exercise performance in resistance-trained females. Eur J Nutr. 2017 Mar;56(2):775-784.