No effect of short-term arginine supplementation on nitric oxide production, metabolism and performance in intermittent exercise in athletes

Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans

“…The most recognised pathway for nitric oxide generation is the oxidation of L-arginine catalysed by the nitric oxide synthase enzymes to yield nitric oxide and L-citrulline [3]. However, while oral L-arginine supplementation can increase circulating [L-arginine] [4,5], and therefore one of the substrates for nitric oxide synthase, whether oral Larginine supplementation increases nitric oxide biomarkers (nitrate and nitrite) and improves exercise performance is controversial [4,[6][7][8][9], see 10 for review]. These conflicting findings might be linked, at least in part, to significant pre-systemic [11,12] and systemic [11,[13][14][15][16] breakdown of orally ingested L-arginine.…”

l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans

“…1 for review). However, when Arg treatment increases NO biomarkers, exercise economy and exercise performance are improved (5, 52), whereas exercise economy and exercise performance are not improved when Arg treatment does not influence NO synthesis (9,31,35,60). Therefore, while there is some evidence to suggest that Arg treatment might improve physiological responses in conjunction with elevated NO synthesis, an optimal Arg administration procedure to enhance NO synthesis and associated physiological responses has yet to be established.…”

“…Approximately 40% of ingested oral Arg is catabolized by intestinal bacteria and arginases on the first pass (13,67), with a further 10 -15% of systemic Arg extracted and metabolized by the liver (13,44,48,59,71). While acute (57) and short-term (35) Arg ingestion have been shown to increase plasma Arg concentration ([Arg]), the intracellular utilization of this additional substrate by NOS might be restricted by the competition between Arg, asymmetric dimethylarginine (ADMA), and other Arg analogs for the transporter y ϩ carrier hCAT-2B (14). This regulation of Arg transport and metabolism could account for the finding that only ϳ1% of an oral Arg dose is utilized as substrate by NOS (11).…”

Effect of pre-exercise single dose arginine ingestion on plasma amino acid profile during exhaustive exercise in elite male wrestlers

“…Water intake was not allowed during the exercise protocol. The washout period for arginine used in the literature changes as 4 days [7], 7 days [12,21,22] and 10 days [23] in different studies. In this study, subject was randomly assigned to arginine or placebo trial separated by a week of washout period.…”

“…Review analysis [4] of the effect of both oral and intravenous arginine administration on metabolism at rest and during exercise emphasized that arginine supplementation appears to improve exercise capacity in individuals with cardiovascular disease, but had little impact on aerobic exercise capacity in healthy individuals [4]; while a very recent review claims that there is no clear evidence that arginine supplementation increases the performance regardless of the aerobic or anaerobic nature of the exercise and it is still premature to recommend dietary supplements containing arginine as an ergogenic aid for healthy physically active subjects [1]. There were only five acute studies retrieved from the literature that evaluated exercise performance after arginine supplementation [5][6][7][8][9], three of which reported significant improvements [5,6,9]. Arginine is the only substrate for endogenous synthesis of nitric oxide (NO).…”