Abstract
Purpose
Nitrate-rich beetroot juice supplementation has been extensively used to increase exercise economy in different populations. However, its use in elite distance runners, and its potential effects on biomechanical aspects of running have not been properly investigated. This study aims to analyze the potential effects of 15 days of beetroot juice supplementation on physiological, psychological and biomechanical variables in elite runners.
Methods
Twelve elite middle and long-distance runners (age = 26.3 ± 5.1yrs, VO2Max = 71.8±5.2 ml*kg-1*min-1) completed an incremental running test to exhaustion on a treadmill before and after a 15-days supplementation period, in which half of the group (EG) consumed a daily nitrate-rich beetroot juice and the other group (PG) consumed a placebo drink. Time to exhaustion (TEx), running economy, vastus lateralis oxygen saturation (SmO2), leg stiffness and rate of perceived exertion (RPE) were measured at 15, 17.1 and 20 km/h during the incremental test.
Results
Likely to very likely improvements in EG were observed for the RPE (Standardized mean difference (SMD) = -2.17, 90%CI = -3.23, -1.1), SmO2 (SMD = 0.72, 90%CI = 0.03, 1.41) and TEx (SMD = 1.18, 90%CI = -0.14, 2.5) in comparison with PG. No other physiological or biomechanical variable showed substantial improvements after the supplementation period.
Conclusions
Fifteen days of nitrate-rich beetroot juice supplementation produced substantial improvements in the time to exhaustion in elite runners; however, it didn’t produce meaningful improvements in running economy, VO2Max or mechanical parameters.
Citation: Balsalobre-Fernández C, Romero-Moraleda B, Cupeiro R, Peinado AB, Butragueño J, Benito PJ (2018) The effects of beetroot juice supplementation on exercise economy, rating of perceived exertion and running mechanics in elite distance runners: A double-blinded, randomized study. PLoS ONE 13(7):
e0200517.
https://doi.org/10.1371/journal.pone.0200517
Editor: Gordon Fisher, University of Alabama at Birmingham, UNITED STATES
Received: March 15, 2018; Accepted: June 26, 2018; Published: July 11, 2018
Copyright: © 2018 Balsalobre-Fernández et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Data are available from figshare (https://doi.org/10.6084/m9.figshare.5873190.v1).
Funding: The authors received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Description
This study analyzes the effects of beetroot juice on elite runners' performance.