School of Physiotherapy, Faculty of Health Sciences, Universidad Francisco de Vitoria, 28223 Madrid, Spain.
Department of Biomedical Sciences, Area of Sport and Physical Education, Faculty of Medicine and Health Sciences, University of Alcalá, 28805 Madrid, Spain.
Nutrients. 2020 Feb 23;12(2):584. doi: 10.3390/nu12020584.
Beetroot juice (BJ) contains high levels of inorganic nitrate (NO) and its intake has good evidence in increasing blood nitrate/nitrite concentrations. The ingestion of BJ has been associated with improvements in physical performance of endurance sports, however the literature in intermittent sports is scarce. The aim of this study was to investigate whether BJ could improve physical performance in tennis players. Thirteen well-trained tennis players (25.4 ± 5.1 years) participated in the study during their preparatory period for the tennis season. Subjects were randomly divided into two groups and performed a neuromuscular test battery after either BJ or placebo (PLA) consumption. Both trials were executed on two separate days, in randomized order, with one week of wash out period. The test battery consisted of serve velocity test (SVT), countermovement jump (CMJ), isometric handgrip strength (IHS), 5-0-5 agility test (5-0-5), and 10 m sprint (10-m). No significant differences were found in SVT (1.19%; = 0.536), CMJ (0.96%; = 0.327), IHS (4.06%; = 0.069), 5-0-5 dominant and nondominant side (1.11-2.02%; = 0.071-0.191) and 10-m (1.05%; = 0.277) when comparing BJ and PLA ingestion. Thus, our data suggest that low doses of BJ (70 mL) consumption do not enhance tennis physical performance.
甜菜根汁（BJ）含有高水平的无机硝酸盐（NO），其摄入能有效提高血液硝酸盐/亚硝酸盐浓度。BJ 的摄入与耐力运动的身体表现的改善有关，但间歇性运动的文献却很少。本研究旨在探讨 BJ 是否可以提高网球运动员的身体表现。13 名训练有素的网球运动员（25.4±5.1 岁）在网球赛季的准备期间参加了这项研究。受试者随机分为两组，分别在饮用 BJ 或安慰剂（PLA）后进行神经肌肉测试。两次试验均在两天内、随机顺序进行，洗脱期为一周。测试包括发球速度测试（SVT）、反跳测试（CMJ）、等长握力测试（IHS）、5-0-5 敏捷测试（5-0-5）和 10 米冲刺（10-m）。SVT（1.19%， = 0.536）、CMJ（0.96%， = 0.327）、IHS（4.06%， = 0.069）、5-0-5 主导和非主导侧（1.11-2.02%， = 0.071-0.191）和 10-m（1.05%， = 0.277）的测试结果无显著差异。因此，我们的数据表明，低剂量 BJ（70ml）的摄入并不能提高网球运动员的身体表现。
