No effect of acute l-arginine supplementation on O2 cost or exercise tolerance

• Published in: European journal of applied physiology Vol. 113; no. 7; pp. 1805 - 1819
• Main Authors: Vanhatalo, Anni, Bailey, Stephen J., DiMenna, Fred J., Blackwell, Jamie R., Wallis, Gareth A., Jones, Andrew M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2013; Springer Nature B.V
• Subjects: Adult; Arginine - pharmacology; Biomarkers; Biomedical and Life Sciences; Biomedicine; Carbohydrates - pharmacology; Dietary Supplements; Double-Blind Method; Environmental science; Exercise Tolerance - drug effects; Human Physiology; Humans; Male; Musculoskeletal system; Nitrates; Nitric oxide; Nitrites - blood; Occupational Medicine/Industrial Medicine; Original Article; Oxygen Consumption - drug effects; Physiology; Running; Sports Medicine; United States > US; Blood pressure; Dietary supplementation; Exercise efficiency; Nitric oxide
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-013-2593-z

The extent to which dietary supplementation with the nitric oxide synthase (NOS) substrate, l -arginine (ARG), impacts on NO production and NO-mediated physiological responses is controversial. This randomised, double blinded, cross-over study investigated the effects of acute ARG supplementation on NO biomarkers, O 2 cost of exercise and exercise tolerance in humans. In one experiment, 15 subjects completed moderate- and severe-intensity running bouts after acute supplementation with 6 g ARG or placebo (PLA). In another experiment, eight subjects completed moderate- and severe-intensity cycling bouts after acute supplementation with 6 g ARG plus 25 g of carbohydrate (ARG + CHO) or an energy-matched dose of carbohydrate alone (CHO). The plasma nitrite concentration was not different after ARG (Pre: 204 ± 79; Post: 241 ± 114 nM; P  > 0.05) or ARG + CHO consumption (Pre: 304 ± 57; Post: 335 ± 116 nM; P  > 0.05). During moderate-intensity exercise, the steady-state pulmonary was not different, relative to the respective placebo conditions, after ARG (PLA: 2,407 ± 318, ARG: 2,422 ± 333 mL min −1 ) or ARG + CHO (CHO: 1,695 ± 304, ARG + CHO: 1,712 ± 312 mL min −1 ) ingestion ( P  > 0.05). The tolerable duration of severe exercise was also not significantly different ( P  > 0.05) after ingesting ARG (PLA: 551 ± 140, ARG: 552 ± 150 s) or ARG + CHO (CHO: 457 ± 182, ARG + CHO: 441 ± 221 s). In conclusion, acute dietary supplementation with ARG or ARG + CHO did not alter biomarkers of NO synthesis, O 2 cost of exercise or exercise tolerance in healthy subjects.