L-arginne Supplementation has no effect on exercise tolerance or O2 cost

No effect of acute L-arginine supplementation on O(2) cost or exercise tolerance.


Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke’s Campus, Exeter, Devon, EX1 2LU, UK.


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 [Formula: see text] 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.

About The Athlete Clinic

Coaching & Athlete Services including, Coaching, Fitness & Physiological Testing, Physical Therapy, Orthopaedic Sports Massage & Injury Management, Strength & Conditioning, Athlete & Group Development Programs, Research & Development Programs
This entry was posted in Reviews and tagged , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s