Brief ReviewEffects of Citrulline Supplementation on Exercise Performance in Humans A Review of the Current LiteratureGonzalez, Adam M.1; Trexler, Eric T.2Author Information 1Department of Health Professions, Hofstra University, Hempstead, New York; and 2Stronger By Science LLC, Chapel Hill, North Carolina Address correspondence to Dr. Adam M. Gonzalez, Adam.Gonzalez@hofstra.edu. Online date: January 22, 2020 Journal of Strength and Conditioning Research: May 2020 - Volume 34 - Issue 5 - p 1480-1495 doi: 10.1519/JSC.0000000000003426 Buy Metrics Abstract Gonzalez, AM and Trexler, ET. Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. J Strength Cond Res 34(5): 1480–1495, 2020—L-citrulline, a nonessential amino acid found primarily in watermelon, has recently garnered much attention for its potential to augment L-arginine bioavailability, nitric oxide production, and exercise performance. Over the past decade, L-citrulline has received considerable scientific attention examining potentially ergogenic properties for both aerobic and anaerobic exercise performance. Thus, the purpose of this article is to summarize the theoretical rationale behind L-citrulline supplementation and to comprehensively review the available scientific evidence assessing the potential ergogenic value of L-citrulline supplementation on vascular function and exercise performance in humans. In addition, research that has investigated the potential synergistic effects of L-citrulline with other dietary ingredients (e.g., arginine, antioxidants, nitrates, and branched-chain amino acids) is reviewed. Oral L-citrulline and citrulline malate supplementation have shown to increase plasma citrulline and arginine concentrations, along with total nitrate and nitrite concentrations. Although blood flow enhancement is a proposed mechanism for the ergogenic potential of L-citrulline, evidence supporting acute improvements in vasodilation and skeletal muscle tissue perfusion after supplementation is scarce and inconsistent. Nevertheless, several studies have reported that L-citrulline supplementation can enhance exercise performance and recovery. Given the positive effects observed from some investigations, future studies should continue to investigate the effects of both acute and chronic supplementation with L-citrulline and citrulline malate on markers of blood flow and exercise performance and should seek to elucidate the mechanism underlying such effects. Copyright © 2020 by the National Strength & Conditioning Association.