The effect of variable doses of inorganic nitrate-rich beetroot juice on simulated 2000-m rowing performance in trained athletes
(Die Wirkung unterschiedlicher Dosierungen anorganischen nitratreichen Rote-Beete-Safts auf die simulierte 2000-m-Ruderleistung bei trainierten Sportlern)
Context: Beetroot juice is a naturally rich source of inorganic nitrate (NO3-), a compound hypothesized to enhance endurance performance by improving exercise efficiency. Purpose: To investigate the effect of different doses of beetroot juice on 2000-m ergometer-rowing performance in highly trained athletes. Methods: Ten highly trained male rowers volunteered to participate in a placebo-controlled, double-blinded crossover study. Two hours before undertaking a 2000-m rowing-ergometer test, subjects consumed beetroot juice containing 0 mmol (placebo), 4.2 mmol (SINGLE), or 8.4 mmol (DOUBLE) NO3-. Blood samples were taken before supplement ingestion and immediately before the rowing test for analysis of plasma [NO3-] and [nitrite (NO2-)]. Results: The SINGLE dose demonstrated a trivial effect on time to complete 2000 m compared with placebo (mean difference: 0.2 ± 2.5 s). A possibly beneficial effect was found with DOUBLE compared with SINGLE (mean difference -1.8 ± 2.1 s) and with placebo (-1.6 ± 1.6 s). Plasma [NO2-] and [NO3-] demonstrated a dose-response effect, with greater amounts of ingested nitrate leading to substantially higher concentrations (DOUBLE > SINGLE > placebo). There was a moderate but insignificant correlation (r = -.593, P = .055) between change in plasma [NO2-] and performance time. Conclusion: Compared with nitratedepleted beetroot juice, a high (8.4 mmol NO3-) but not moderate (4.2 mmol NO3-) dose of NO3- in beetroot juice, consumed 2 h before exercise, may improve 2000-m rowing performance in highly trained athletes.
© Copyright 2014 International Journal of Sports Physiology and Performance. Alle Rechte vorbehalten.
Schlagworte: | Rudern Ernährung Supplementierung ergogenes Mittel |
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Notationen: | Biowissenschaften und Sportmedizin Ausdauersportarten |
DOI: | 10.1123/IJSPP.2013-0207 |
Veröffentlicht in: | International Journal of Sports Physiology and Performance |
Veröffentlicht: |
2014
|
Jahrgang: | 9 |
Heft: | 4 |
Seiten: | 615-620 |
Dokumentenarten: | Artikel |
Sprache: | Englisch |
Level: | hoch |