Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Export

@article{citeulike:5955190, abstract = {Pharmacological sodium nitrate supplementation has been reported to reduce the O(2) cost of submaximal exercise in humans. In this study, we hypothesized that dietary supplementation with inorganic nitrate in the form of beetroot juice (BR) would reduce the O(2) cost of submaximal exercise and enhance the tolerance to high-intensity exercise. In a double-blind, placebo (PL)-controlled, crossover study, eight men (aged 19-38 yr) consumed 500 ml/day of either BR (containing 11.2 +/- 0.6 mM of nitrate) or blackcurrant cordial (as a PL, with negligible nitrate content) for 6 consecutive days and completed a series of "step" moderate-intensity and severe-intensity exercise tests on the last 3 days. On days 4-6, plasma nitrite concentration was significantly greater following dietary nitrate supplementation compared with PL (BR: 273 +/- 44 vs. PL: 140 +/- 50 nM; P < 0.05), and systolic blood pressure was significantly reduced (BR: 124 +/- 2 vs. PL: 132 +/- 5 mmHg; P < 0.01). During moderate exercise, nitrate supplementation reduced muscle fractional O(2) extraction (as estimated using near-infrared spectroscopy). The gain of the increase in pulmonary O(2) uptake following the onset of moderate exercise was reduced by 19\% in the BR condition (BR: 8.6 +/- 0.7 vs. PL: 10.8 +/- 1.6 ml.min(-1).W(-1); P < 0.05). During severe exercise, the O(2) uptake slow component was reduced (BR: 0.57 +/- 0.20 vs. PL: 0.74 +/- 0.24 l/min; P < 0.05), and the time-to-exhaustion was extended (BR: 675 +/- 203 vs. PL: 583 +/- 145 s; P < 0.05). The reduced O(2) cost of exercise following increased dietary nitrate intake has important implications for our understanding of the factors that regulate mitochondrial respiration and muscle contractile energetics in humans.}, author = {Bailey, Stephen J. and Winyard, Paul and Vanhatalo, Anni and Blackwell, Jamie R. and Dimenna, Fred J. and Wilkerson, Daryl P. and Tarr, Joanna and Benjamin, Nigel and Jones, Andrew M.}, citeulike-article-id = {5955190}, citeulike-linkout-0 = {http://dx.doi.org/10.1152/japplphysiol.00722.2009}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19661447}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19661447}, doi = {10.1152/japplphysiol.00722.2009}, issn = {1522-1601}, journal = {Journal of applied physiology (Bethesda, Md. : 1985)}, month = {October}, number = {4}, pages = {1144--1155}, posted-at = {2009-10-17 03:25:59}, priority = {2}, title = {Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans.}, url = {http://dx.doi.org/10.1152/japplphysiol.00722.2009}, volume = {107}, year = {2009} }

TY - JOUR ID - citeulike:5955190 L3 - citeulike-article-id:5955190 N2 - Pharmacological sodium nitrate supplementation has been reported to reduce the O(2) cost of submaximal exercise in humans. In this study, we hypothesized that dietary supplementation with inorganic nitrate in the form of beetroot juice (BR) would reduce the O(2) cost of submaximal exercise and enhance the tolerance to high-intensity exercise. In a double-blind, placebo (PL)-controlled, crossover study, eight men (aged 19-38 yr) consumed 500 ml/day of either BR (containing 11.2 +/- 0.6 mM of nitrate) or blackcurrant cordial (as a PL, with negligible nitrate content) for 6 consecutive days and completed a series of "step" moderate-intensity and severe-intensity exercise tests on the last 3 days. On days 4-6, plasma nitrite concentration was significantly greater following dietary nitrate supplementation compared with PL (BR: 273 +/- 44 vs. PL: 140 +/- 50 nM; P < 0.05), and systolic blood pressure was significantly reduced (BR: 124 +/- 2 vs. PL: 132 +/- 5 mmHg; P < 0.01). During moderate exercise, nitrate supplementation reduced muscle fractional O(2) extraction (as estimated using near-infrared spectroscopy). The gain of the increase in pulmonary O(2) uptake following the onset of moderate exercise was reduced by 19% in the BR condition (BR: 8.6 +/- 0.7 vs. PL: 10.8 +/- 1.6 ml.min(-1).W(-1); P < 0.05). During severe exercise, the O(2) uptake slow component was reduced (BR: 0.57 +/- 0.20 vs. PL: 0.74 +/- 0.24 l/min; P < 0.05), and the time-to-exhaustion was extended (BR: 675 +/- 203 vs. PL: 583 +/- 145 s; P < 0.05). The reduced O(2) cost of exercise following increased dietary nitrate intake has important implications for our understanding of the factors that regulate mitochondrial respiration and muscle contractile energetics in humans. IS - 4 JF - Journal of applied physiology (Bethesda, Md. : 1985) SN - 1522-1601 EP - 1155 TI - Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. VL - 107 SP - 1144 AU - Bailey, Stephen AU - Winyard, Paul AU - Vanhatalo, Anni AU - Blackwell, Jamie AU - Dimenna, Fred AU - Wilkerson, Daryl AU - Tarr, Joanna AU - Benjamin, Nigel AU - Jones, Andrew PY - 2009/10// UR - http://dx.doi.org/10.1152/japplphysiol.00722.2009 ER -