Acute and chronic effects of dietary nitrate supplementation on blood pressure and the physiological responses to moderate-intensity and incremental exercise

作者：Vanhatalo Anni; Bailey Stephen J; Blackwell Jamie R; DiMenna Fred J; Pavey Toby G; Wilkerson Daryl P; Benjamin Nigel; Winyard Paul G; Jones Andrew M^*

来源：American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, 2010, 299(4): R1121-R1131.

DOI：10.1152/ajpregu.00206.2010

• beetroot juice
• O(2) uptake
• ramp exercise
• performance
• nitric oxide

Vanhatalo A, Bailey SJ, Blackwell JR, DiMenna FJ, Pavey TG, Wilkerson DP, Benjamin N, Winyard PG, Jones AM. Acute and chronic effects of dietary nitrate supplementation on blood pressure and the physiological responses to moderate-intensity and incremental exercise. Am J Physiol Regul Integr Comp Physiol 299: R1121-R1131, 2010. First published August 11, 2010; doi:10.1152/ajpregu.00206.2010.-Dietary nitrate (NO(3)(-)) supplementation with beetroot juice (BR) over 4-6 days has been shown to reduce the O(2) cost of submaximal exercise and to improve exercise tolerance. However, it is not known whether shorter (or longer) periods of supplementation have similar (or greater) effects. We therefore investigated the effects of acute and chronic NO(3) supplementation on resting blood pressure (BP) and the physiological responses to moderate-intensity exercise and ramp incremental cycle exercise in eight healthy subjects. Following baseline tests, the subjects were assigned in a balanced crossover design to receive BR (0.5 l/day; 5.2 mmol of NO(3)(-)/day) and placebo (PL; 0.5 l/day low-calorie juice cordial) treatments. The exercise protocol (two moderate-intensity step tests followed by a ramp test) was repeated 2.5 h following first ingestion (0.5 liter) and after 5 and 15 days of BR and PL. Plasma nitrite concentration (baseline: 454 +/- 81 nM) was significantly elevated (+39% at 2.5 h postingestion; +25% at 5 days; +46% at 15 days; P < 0.05) and systolic and diastolic BP (baseline: 127 +/- 6 and 72 +/- 5 mmHg, respectively) were reduced by similar to 4% throughout the BR supplementation period (P < 0.05). Compared with PL, the steady-state (V) over dotO(2) during moderate exercise was reduced by similar to 4% after 2.5 h and remained similarly reduced after 5 and 15 days of BR (P < 0.05). The ramp test peak power and the work rate at the gas exchange threshold (baseline: 322 +/- 67 W and 89 +/- 15 W, respectively) were elevated after 15 days of BR (331 +/- 68 W and 105 +/- 28 W; P < 0.05) but not PL (323 +/- 68 W and 84 +/- 18 W). These results indicate that dietary NO(3)(-) supplementation acutely reduces BP and the O(2) cost of submaximal exercise and that these effects are maintained for at least 15 days if supplementation is continued.

• 出版日期2010-10