Jones Andrew M, Vanhatalo Anni, Bailey Stephen J
Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
Nestle Nutr Inst Workshop Ser. 2013;75:27-40. doi: 10.1159/000345815. Epub 2013 Apr 16.
Several recent studies indicate that supplementation of the diet with inorganic nitrate results in a significant reduction in pulmonary O2 uptake during sub-maximal exercise, an effect that appears to be related to enhanced skeletal muscle efficiency. The physiological mechanisms responsible for this effect are not completely understood but are presumably linked to the bioconversion of ingested nitrate into nitrite and thence to nitric oxide. Nitrite and/or nitric oxide may influence muscle contractile efficiency perhaps via effects on sarcoplasmic reticulum calcium handling or actin-myosin interaction, and may also improve the efficiency of mitochondrial oxidative phosphorylation. A reduced O2 cost of exercise can be observed within 3 h of the consumption of 5-6 mmol of nitrate, and this effect can be preserved for at least 15 days provided that the same 'dose' of nitrate is consumed daily. A reduced O2 cost of exercise following nitrate supplementation has now been reported for several types of exercise including cycling, walking, running, and knee extension exercise. Dietary nitrate supplementation has been reported to extend the time to exhaustion during high-intensity constant work rate exercise by 16-25% and to enhance cycling performance over 4, 10, and 16.1 km by 1-2% in recreationally active and moderately trained subjects. Although nitrate appears to be a promising 'new' ergogenic aid, additional research is required to determine the scope of its effects in different populations and different types of exercise.
最近的几项研究表明，饮食中补充无机硝酸盐可使次最大运动期间的肺部氧气摄取量显著降低，这一效应似乎与骨骼肌效率提高有关。导致这种效应的生理机制尚未完全了解，但推测与摄入的硝酸盐生物转化为亚硝酸盐并进而转化为一氧化氮有关。亚硝酸盐和/或一氧化氮可能通过影响肌浆网钙处理或肌动蛋白-肌球蛋白相互作用来影响肌肉收缩效率，还可能提高线粒体氧化磷酸化的效率。在摄入5-6 mmol硝酸盐后3小时内即可观察到运动时氧气消耗减少，并且只要每天摄入相同“剂量”的硝酸盐，这种效应可维持至少15天。现在已有报道称，补充硝酸盐后，包括骑自行车、步行、跑步和伸膝运动在内的几种运动类型的运动时氧气消耗都会减少。据报道，在休闲活跃和适度训练的受试者中，饮食中补充硝酸盐可使高强度恒定工作率运动中的疲劳时间延长16%-25%，并使4公里、10公里和16.1公里的骑行表现提高1%-2%。尽管硝酸盐似乎是一种有前景的“新型”促力剂，但仍需要更多研究来确定其在不同人群和不同运动类型中的作用范围。
