UCD Institute for Sport & Health, School of Public Health, Physiotherapy, and Sports Science, University College Dublin , Dublin, Ireland.
Florida Institute for Human and Machine Cognition , Pensacola, FL, USA.
J Sports Sci. 2020 Sep;38(18):2063-2070. doi: 10.1080/02640414.2020.1770409. Epub 2020 Jun 7.
The effects of acute ingestion of nitrate on short-duration repeated sprint performance (RSP) are unclear. This study investigated the effect of acute ingestion of beetroot juice on a test of RSP in team sport athletes. Sixteen male team sport athletes undertook four trials using a 40 m maximum shuttle run test (MST), which incorporates 10 × 40 m shuttle sprints with 30 s between the start of each sprint. Two familiarisation trials, followed by nitrate-rich beetroot juice (BR; ~6 mmol nitrate) and nitrate-depleted beetroot juice (PLA; ~0.0034 mmol nitrate) trials were completed in a randomised, double-blind manner. Ingestion of beetroot juice 3 h prior to exercise elevated plasma nitrate concentrations ~6-fold in BR (BR, 413 ± 56 μM; PLA, 69 ± 30 μM; P < 0.001). RSP, assessed by sprint performance decrement (S; %), did not differ (P = 0.337) between BR (5.31 ± 2.49%) and PLA (5.71 ± 2.61%). There was no difference between trials for total sprint time (P = 0.806), fastest sprint (P = 0.341), slowest sprint (P = 0.787), or post-exercise blood lactate concentration (BR, 11.8 ± 2.5 mM; PLA, 12.2 ± 2.3 mM; P = 0.109). Therefore, acute ingestion of beetroot juice did not improve a test of short-duration RSP in team sport athletes.
急性摄入硝酸盐对短时间重复冲刺表现(RSP)的影响尚不清楚。本研究调查了急性摄入甜菜根汁对团队运动运动员 RSP 测试的影响。16 名男性团队运动运动员进行了四次 40 米最大折返跑测试(MST),其中包括 10 次 40 米折返冲刺,每次冲刺之间有 30 秒的休息时间。采用随机、双盲的方式进行了两次熟悉试验,随后分别饮用富含硝酸盐的甜菜根汁(BR;6mmol 硝酸盐)和硝酸盐耗尽的甜菜根汁(PLA;0.0034mmol 硝酸盐)。运动前 3 小时摄入甜菜根汁可使 BR 中的血浆硝酸盐浓度升高约 6 倍(BR,413±56μM;PLA,69±30μM;P<0.001)。BR(5.31±2.49%)和 PLA(5.71±2.61%)的冲刺表现下降(S;%)没有差异(P=0.337)。BR(11.8±2.5mM)和 PLA(12.2±2.3mM)的总冲刺时间(P=0.806)、最快冲刺(P=0.341)、最慢冲刺(P=0.787)和运动后血乳酸浓度(P=0.109)也没有差异。因此,急性摄入甜菜根汁并不能提高团队运动运动员的短时间 RSP 测试成绩。