In:
Journal of Applied Physiology, American Physiological Society, Vol. 109, No. 5 ( 2010-11), p. 1394-1403
Kurzfassung:
It has recently been reported that dietary nitrate (NO 3 − ) supplementation, which increases plasma nitrite (NO 2 − ) concentration, a biomarker of nitric oxide (NO) availability, improves exercise efficiency and exercise tolerance in healthy humans. We hypothesized that dietary supplementation with l-arginine, the substrate for NO synthase (NOS), would elicit similar responses. In a double-blind, crossover study, nine healthy men (aged 19–38 yr) consumed 500 ml of a beverage containing 6 g of l-arginine (Arg) or a placebo beverage (PL) and completed a series of “step” moderate- and severe-intensity exercise bouts 1 h after ingestion of the beverage. Plasma NO 2 − concentration was significantly greater in the Arg than the PL group (331 ± 198 vs. 159 ± 102 nM, P 〈 0.05) and systolic blood pressure was significantly reduced (123 ± 3 vs. 131 ± 5 mmHg, P 〈 0.01). The steady-state O 2 uptake (V̇o 2 ) during moderate-intensity exercise was reduced by 7% in the Arg group (1.48 ± 0.12 vs. 1.59 ± 0.14 l/min, P 〈 0.05). During severe-intensity exercise, the V̇o 2 slow component amplitude was reduced (0.58 ± 0.23 and 0.76 ± 0.29 l/min in Arg and PL, respectively, P 〈 0.05) and the time to exhaustion was extended (707 ± 232 and 562 ± 145 s in Arg and PL, respectively, P 〈 0.05) following consumption of Arg. In conclusion, similar to the effects of increased dietary NO 3 − intake, elevating NO bioavailability through dietary l-Arg supplementation reduced the O 2 cost of moderate-intensity exercise and blunted the V̇o 2 slow component and extended the time to exhaustion during severe-intensity exercise.
Materialart:
Online-Ressource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/japplphysiol.00503.2010
Sprache:
Englisch
Verlag:
American Physiological Society
Publikationsdatum:
2010
ZDB Id:
1404365-8
SSG:
12
SSG:
31
