Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance.
Recent studies have suggested that dietary inorganic nitrate (NO₃(-)) supplementation may improve muscle efficiency and endurance exercise tolerance but possible effects during team sport-specific intense intermittent exercise have not been examined. We hypothesized that NO₃(-) supplementation would enhance high-intensity intermittent exercise performance. Fourteen male recreational team-sport players were assigned in a double-blind, randomized, crossover design to consume 490 mL of concentrated, nitrate-rich beetroot juice (BR) and nitrate-depleted placebo juice (PL) over ~30 h preceding the completion of a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1). Resting plasma nitrite concentration ([NO₂(-)]) was ~400% greater in BR compared to PL. Plasma [NO₂(-)] declined by 20% in PL (P < 0.05) and by 54 % in BR (P < 0.05) from pre-exercise to end-exercise. Performance in the Yo-Yo IR1 was 4.2% greater (P < 0.05) with BR (1,704 ± 304 m) compared to PL (1,636 ± 288 m). Blood [lactate] was not different between BR and PL, but the mean blood [glucose] was lower (3.8 ± 0.8 vs. 4.2 ± 1.1 mM, P < 0.05) and the rise in plasma [K(+)] tended to be reduced in BR compared to PL (P = 0.08). These findings suggest that NO₃(-) supplementation may promote NO production via the nitrate-nitrite-NO pathway and enhance Yo-Yo IR1 test performance, perhaps by facilitating greater muscle glucose uptake or by better maintaining muscle excitability. Dietary NO₃(-) supplementation improves performance during intense intermittent exercise and may be a useful ergogenic aid for team sports players.
Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter EX1 2LU, UK.
Lee J
LJ
Wylie
Magni
M
Mohr
Peter
P
Krustrup
Sarah R
SR
Jackman
Georgios
G
Ermιdis
James
J
Kelly
Matthew I
MI
Black
Stephen J
SJ
Bailey
Anni
A
Vanhatalo
Andrew M
AM
Jones
D054874:Athletic Performance; D027461:Beta vulgaris / Q000737:chemistry; D001628:Beverages; D001786:Blood Glucose; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise; D006801:Humans; D008297:Male; D009566:Nitrates / Q000008:administration & dosage* / Q000097:blood; D009573:Nitrites / Q000097:blood; D011188:Potassium / Q000097:blood; D055815:Young Adult
D001786:Blood Glucose; D009566:Nitrates; D009573:Nitrites; D011188:Potassium