Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study
Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study
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DOI：
10.1152/japplphysiol.01070.2010
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发表时间：
2011-03-01
影响因子：
3.3
通讯作者：
Jones, Andrew M.
中科院分区：
文献类型：
--
作者：
Lansley, Katherine E.;Winyard, Paul G.;Jones, Andrew M.
Lansley KE，Winyard PG，Fulford J，Vanhatalo A，Bailey SJ，Blackwell JR，DiMenna FJ，Gilchrist M，Benjamin N，Jones AM.膳食硝酸盐补充剂降低了步行和跑步的O-2成本：一项安慰剂对照研究J Appl Physiol 110：591-600，2011.首次发表于2010年11月11日; doi：10.1152/japplphysiol.01070.2010.-膳食补充甜菜根汁（BR）已被证明可以降低静息血压和亚极量运动的O-2消耗，并增加对高强度自行车运动的耐受性。我们测试的假设，BR的生理效应是由于其本身的高NO3-含量，而不是其他潜在的生物活性化合物的存在。我们研究了血压，线粒体氧化能力（Q（max））的变化，以及在饮食补充BR和NO3-耗尽BR [安慰剂（PL）]后对步行和中度和重度强度跑步的生理反应。在对照（无补充）试验后，9名健康、体力活动的男性受试者被随机、双盲、交叉设计分配接受BR（0.5 l/天，含有类似于6.2 mmol的NO3-）和PL（0.5 l/天，含有类似于0.003 mmol的NO3-）6天。受试者在补充期的第4天和第5天完成跑步机运动试验，并在第6天完成膝关节伸展运动试验以估计Q（max）（使用P-31-磁共振波谱）。相对于PL，BR升高血浆NO2-浓度（183 +/- 119 vs. 373 +/- 211 nM，P < 0.05）并降低收缩压（129 +/- 9 vs. 124 +/- 10 mmHg，P < 0.01）。PL和BR之间的Q（max）无差异（分别为0.93 +/- 0.05和1.05 +/- 0.22 mM/s）。步行的O-2成本（PL和BR分别为0.87 +/- 0.12和0.70 +/- 0.10 l/min，P < 0.01），中等强度跑步（PL和BR分别为2.26 +/- 0.27和2.10 +/- 0.28 l/min，P < 0.01），和高强度的跑步（PL和BL的运动终了O-2摄取量分别为3.77 +/- 0.57和3.50 +/- 0.62 l/min，P < 0.01）被BR降低，在高强度跑中，力竭时间增加了15%（PL和BR分别为7.6 ± 1.5和8.7 ± 1.8min，P < 0.01）。相反，相对于对照组，PL补充并没有改变血浆NO2-浓度，血压，或运动的生理反应。这些结果表明，6天的BR补充对运动的生理反应的积极影响可以归因于高NO3-含量本身。
Lansley KE, Winyard PG, Fulford J, Vanhatalo A, Bailey SJ, Blackwell JR, DiMenna FJ, Gilchrist M, Benjamin N, Jones AM. Dietary nitrate supplementation reduces the O-2 cost of walking and running: a placebo-controlled study. J Appl Physiol 110:591-600, 2011. First published November 11, 2010; doi:10.1152/japplphysiol.01070.2010.-Dietary supplementation with beetroot juice (BR) has been shown to reduce resting blood pressure and the O-2 cost of submaximal exercise and to increase tolerance to high-intensity cycling. We tested the hypothesis that the physiological effects of BR were consequent to its high NO3- content per se, and not the presence of other potentially bioactive compounds. We investigated changes in blood pressure, mitochondrial oxidative capacity (Q(max)), and physiological responses to walking and moderate-and severe-intensity running following dietary supplementation with BR and NO3--depleted BR [placebo (PL)]. After control (nonsupplemented) tests, nine healthy, physically active male subjects were assigned in a randomized, double-blind, crossover design to receive BR (0.5 l/day, containing similar to 6.2 mmol of NO3-) and PL (0.5 l/day, containing similar to 0.003 mmol of NO3-) for 6 days. Subjects completed treadmill exercise tests on days 4 and 5 and knee-extension exercise tests for estimation of Q(max) (using P-31-magnetic resonance spectroscopy) on day 6 of the supplementation periods. Relative to PL, BR elevated plasma NO2- concentration (183 +/- 119 vs. 373 +/- 211 nM, P < 0.05) and reduced systolic blood pressure (129 +/- 9 vs. 124 +/- 10 mmHg, P < 0.01). Q(max) was not different between PL and BR (0.93 +/- 0.05 and 1.05 +/- 0.22 mM/s, respectively). The O-2 cost of walking (0.87 +/- 0.12 and 0.70 +/- 0.10 l/min in PL and BR, respectively, P < 0.01), moderate-intensity running (2.26 +/- 0.27 and 2.10 +/- 0.28 l/min in PL and BR, respectively, P < 0.01), and severe-intensity running (end-exercise O-2 uptake = 3.77 +/- 0.57 and 3.50 +/- 0.62 l/min in PL and BL, respectively, P < 0.01) was reduced by BR, and time to exhaustion during severe-intensity running was increased by 15% (7.6 +/- 1.5 and 8.7 +/- 1.8 min in PL and BR, respectively, P < 0.01). In contrast, relative to control, PL supplementation did not alter plasma NO2- concentration, blood pressure, or the physiological responses to exercise. These results indicate that the positive effects of 6 days of BR supplementation on the physiological responses to exercise can be ascribed to the high NO3- content per se.