Does Citrulline Malate Enhance Physical Performance

Abstract : The purpose of this study was to investigate the ability of citrulline malate (CM) to enhance physical performance. Our hypothesis was that CM ingestion prior to exercise would result in increased maximal or peak oxygen consumption and time-to-exhaustion. Twelve subjects, 7 men and 5 women, after signing their consent and completing medical screening, participated in this randomized double blind, repeated measures design. Each subject completed three VO2max testing sessions. Initial testing was accomplished to provide a baseline for their secondary and tertiary tests. Following this baseline test, subjects ingested 6 g/d of either CM or a placebo for 14 days. Subjects then returned for their second VO2 max test. After the second test, subjects ingested 6 g/d of the other condition's capsules for 14 days, and then returned for their third and final VO2 max test. VO2max, lactate threshold, maximum watts reached, ratings of perceived exertion and pre- and post-test blood urea nitrogen levels were compared between conditions. There were no significant differences between groups for any of the performance variables measured nor was there a difference between groups in RPE. Although previous studies have claimed to observe an ergogenic effect of CM ingestion, its effects do not appear to include enhancing maximal oxygen uptake or exercise time-to-exhaustion.