Thompson Christopher, Wylie Lee J, Blackwell Jamie R, Fulford Jonathan, Black Matthew I, Kelly James, McDonagh Sinead T J, Carter James, Bailey Stephen J, Vanhatalo Anni, Jones Andrew M
Sport and Health Sciences, University of Exeter, Exeter, United Kingdom.
National Institute for Health Research Exeter Clinical Research Facility, University of Exeter, Exeter, United Kingdom; and.
J Appl Physiol (1985). 2017 Mar 1;122(3):642-652. doi: 10.1152/japplphysiol.00909.2016. Epub 2016 Dec 1.
We hypothesized that 4 wk of dietary nitrate supplementation would enhance exercise performance and muscle metabolic adaptations to sprint interval training (SIT). Thirty-six recreationally active subjects, matched on key variables at baseline, completed a series of exercise tests before and following a 4-wk period in which they were allocated to one of the following groups: ) SIT and [Formula: see text]-depleted beetroot juice as a placebo (SIT+PL); ) SIT and [Formula: see text]-rich beetroot juice (~13 mmol [Formula: see text]/day; SIT+BR); or ) no training and [Formula: see text]-rich beetroot juice (NT+BR). During moderate-intensity exercise, pulmonary oxygen uptake was reduced by 4% following 4 wk of SIT+BR and NT+BR ( < 0.05) but not SIT+PL. The peak work rate attained during incremental exercise increased more in SIT+BR than in SIT+PL ( < 0.05) or NT+BR ( < 0.001). The reduction in muscle and blood [lactate] and the increase in muscle pH from preintervention to postintervention were greater at 3 min of severe-intensity exercise in SIT+BR compared with SIT+PL and NT+BR ( < 0.05). However, the change in severe-intensity exercise performance was not different between SIT+BR and SIT+PL ( > 0.05). The relative proportion of type IIx muscle fibers in the vastus lateralis muscle was reduced in SIT+BR only ( < 0.05). These findings suggest that BR supplementation may enhance some aspects of the physiological adaptations to SIT. We investigated the influence of nitrate-rich and nitrate-depleted beetroot juice on the muscle metabolic and physiological adaptations to 4 wk of sprint interval training. Compared with placebo, dietary nitrate supplementation reduced the O cost of submaximal exercise, resulted in greater improvement in incremental (but not severe-intensity) exercise performance, and augmented some muscle metabolic adaptations to training. Nitrate supplementation may facilitate some of the physiological responses to sprint interval training.
我们假设，为期4周的膳食硝酸盐补充会增强运动表现以及肌肉对冲刺间歇训练（SIT）的代谢适应性。36名基线关键变量匹配的休闲运动受试者，在为期4周的时间段前后完成了一系列运动测试，在此期间他们被分配到以下组之一：）SIT组和硝酸盐耗尽的甜菜根汁作为安慰剂（SIT + PL）；）SIT组和富含硝酸盐的甜菜根汁（约13 mmol硝酸盐/天；SIT + BR）；或）无训练组和富含硝酸盐的甜菜根汁（NT + BR）。在中等强度运动期间，SIT + BR组和NT + BR组在4周后肺摄氧量降低了4%（P < 0.05），而SIT + PL组未降低。递增运动期间达到的峰值功率在SIT + BR组比SIT + PL组增加更多（P < 0.05），比NT + BR组增加更多（P < 0.001）。与SIT + PL组和NT + BR组相比，在高强度运动3分钟时，SIT + BR组从干预前到干预后肌肉和血液中[乳酸]的降低以及肌肉pH值的升高更大（P < 0.05）。然而，SIT + BR组和SIT + PL组之间高强度运动表现的变化没有差异（P > 0.05）。仅SIT + BR组股外侧肌中IIx型肌纤维的相对比例降低（P < 0.05）。这些发现表明，补充甜菜根汁可能会增强对SIT生理适应的某些方面。我们研究了富含硝酸盐和耗尽硝酸盐的甜菜根汁对肌肉代谢和对4周冲刺间歇训练的生理适应的影响。与安慰剂相比，膳食硝酸盐补充降低了次最大运动的氧消耗，在递增（但不是高强度）运动表现上有更大改善，并增强了对训练的一些肌肉代谢适应。硝酸盐补充可能有助于对冲刺间歇训练的一些生理反应。
