School of Sport and Health Sciences, St. Luke's Campus, University of Exeter, Exeter, United Kingdom.
J Appl Physiol (1985). 2010 Nov;109(5):1394-403. doi: 10.1152/japplphysiol.00503.2010. Epub 2010 Aug 19.
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 (VO(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 Vo(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 VO(2) slow component and extended the time to exhaustion during severe-intensity exercise.
最近有报道称，饮食中补充硝酸盐（NO3(-)）会增加血浆中亚硝酸盐（NO2(-)）的浓度，而 NO2(-)是一氧化氮（NO）可用性的生物标志物，可提高健康人群的运动效率和运动耐受力。我们假设，饮食补充 NO 合酶（NOS）的底物 L-精氨酸也会产生类似的反应。在一项双盲、交叉研究中，9 名健康男性（年龄 19-38 岁）饮用含有 6 g L-精氨酸（Arg）的 500 ml 饮料或安慰剂饮料（PL），并在摄入饮料后 1 小时内完成一系列“台阶”式中等强度和高强度运动。Arg 组血浆 NO2(-)浓度明显高于 PL 组（331 ± 198 比 159 ± 102 nM，P < 0.05），收缩压明显降低（123 ± 3 比 131 ± 5 mmHg，P < 0.01）。Arg 组中等强度运动时的稳态 O2 摄取量（VO2）降低了 7%（1.48 ± 0.12 比 1.59 ± 0.14 l/min，P < 0.05）。在高强度运动时，VO2 缓慢成分幅度降低（Arg 和 PL 组分别为 0.58 ± 0.23 和 0.76 ± 0.29 l/min，P < 0.05），运动至力竭时间延长（Arg 和 PL 组分别为 707 ± 232 和 562 ± 145 s，P < 0.05）。总之，与增加饮食中 NO3(-)摄入的效果相似，通过饮食补充 L-Arg 提高 NO 生物利用度可降低中等强度运动的 O2 成本，并使 VO2 缓慢成分减弱，延长高强度运动至力竭的时间。
