Beetroot juice ingestion during prolonged moderate-intensity exercise attenuates progressive rise in O2 uptake

R Tan, LJ Wylie, C Thompson, JR Blackwell, SJ Bailey, A Vanhatalo, AM Jones

Research output: Contribution to journalArticlepeer-review

Abstract

<jats:p> Nitrate-rich beetroot juice (BR) supplementation has been shown to increase biomarkers of nitric oxide availability with implications for the physiological responses to exercise. We hypothesized that BR supplementation before and during prolonged moderate-intensity exercise would maintain an elevated plasma nitrite concentration ([[Formula: see text]]), attenuate the expected progressive increase in V̇o<jats:sub>2 </jats:sub>over time, and improve performance in a subsequent time trial (TT). In a double-blind, randomized, crossover design, 12 men completed 2 h of moderate-intensity cycle exercise followed by a 100-kJ TT in three conditions: 1) BR before and 1 h into exercise (BR + BR); 2) BR before and placebo (PL) 1 h into exercise (BR + PL); and 3) PL before and 1 h into exercise (PL + PL). During the 2-h moderate-intensity exercise bout, plasma [[Formula: see text]] declined by ~17% in BR + PL but increased by ~8% in BR + BR such that, at 2 h, plasma [[Formula: see text]] was greater in BR + BR than both BR + PL and PL + PL ( P &lt; 0.05). V̇o<jats:sub>2</jats:sub> was not different among conditions over the first 90 min of exercise but was lower at 120 min in BR + BR (1.73 ± 0.24 l/min) compared with BR + PL (1.80 ± 0.21 l/min; P = 0.08) and PL + PL (1.83 ± 0.27 l/min; P &lt; 0.01). The decline in muscle glycogen concentration over the 2-h exercise bout was attenuated in BR + BR (~28% decline) compared with BR + PL (~44% decline) and PL + PL (~44% decline; n = 9, P &lt; 0.05). TT performance was not different among conditions ( P &gt; 0.05). BR supplementation before and during prolonged moderate-intensity exercise attenuated the progressive rise in V̇o<jats:sub>2 </jats:sub>over time and appeared to reduce muscle glycogen depletion but did not enhance subsequent TT performance. </jats:p><jats:p> NEW &amp; NOTEWORTHY We show for the first time that ingestion of nitrate during exercise preserves elevated plasma [nitrite] and negates the progressive rise in O<jats:sub>2</jats:sub> uptake during prolonged moderate-intensity exercise. </jats:p>
Original languageEnglish
Pages (from-to)1254-1263
Number of pages0
JournalJournal of Applied Physiology
Volume124
Issue number5
DOIs
Publication statusPublished - 1 May 2018

Fingerprint

Dive into the research topics of 'Beetroot juice ingestion during prolonged moderate-intensity exercise attenuates progressive rise in O2 uptake'. Together they form a unique fingerprint.

Cite this