title: Influence of L-citrulline and watermelon supplementation on vascular function and exercise performance.
abstract: L-Citrulline, either synthetic or in watermelon, may improve vascular function through increased L-arginine bioavailability and nitric oxide synthesis. This article analyses potential vascular benefits of L-citrulline and watermelon supplementation at rest and during exercise.
  
  
  
  There is clear evidence that acute L-citrulline ingestion increases plasma L-arginine, the substrate for endothelial nitric oxide synthesis. However, the subsequent acute improvement in nitric oxide production and mediated vasodilation is inconsistent, which likely explains the inability of acute L-citrulline or watermelon to improve exercise tolerance. Recent studies have shown that chronic L-citrulline supplementation increases nitric oxide synthesis, decreases blood pressure, and may increase peripheral blood flow. These changes are paralleled by improvements in skeletal muscle oxygenation and performance during endurance exercise. The antihypertensive effect of L-citrulline/watermelon supplementation is evident in adults with prehypertension or hypertension, but not in normotensives. However, L-citrulline supplementation may attenuate the blood pressure response to exercise in normotensive men.
  
  
  
  The beneficial vascular effects of L-citrulline/watermelon supplementation may stem from improvements in the L-arginine/nitric oxide pathway. Reductions in resting blood pressure with L-citrulline/watermelon supplementation may have major implications for individuals with prehypertension and hypertension. L-Citrulline supplementation, but not acute ingestion, have shown to improve exercise performance in young healthy adults.
authors.affiliation: aDepartment of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, Florida bDepartment of Health and Human Performance, Marymount University, Arlington, Virginia cDepartment of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas, USA.
authors.forename: Arturo
authors.initials: A
authors.lastname: Figueroa
authors.forename: Alexei
authors.initials: A
authors.lastname: Wong
authors.forename: Salvador J
authors.initials: SJ
authors.lastname: Jaime
authors.forename: Joaquin U
authors.initials: JU
authors.lastname: Gonzales
mesh_terms: D000328:Adult; D001120:Arginine / Q000378:metabolism; D001682:Biological Availability; D001794:Blood Pressure / Q000187:drug effects; D002956:Citrulline / Q000378:metabolism / Q000494:pharmacology*; D029773:Citrullus / Q000737:chemistry*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology; D017079:Exercise Tolerance / Q000187:drug effects*; D006801:Humans; D009569:Nitric Oxide / Q000096:biosynthesis; D012039:Regional Blood Flow / Q000187:drug effects*
chemical_list: D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine