Lookup NU author(s): Dr Tom Clifford,
Dr Dean Allerton,
Professor Emma Stevenson
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Canadian Science Publishing, 2017.
For re-use rights please refer to the publisher's terms and conditions.
© 2017, Canadian Science Publishing. All rights reserved.This study examined whether beetroot juice (BTJ) would attenuate inflammation and muscle damage following a marathon. Using a double blind, independent group design, 34 runners (each having completed ca. ~16 previous marathons) consumed either BTJ or an isocaloric placebo (PLA) for 3 days following a marathon. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), muscle soreness, serum cytokines, leucocytosis, creatine kinase (CK), high sensitivity C-reactive protein (hs-CRP), and aspartate aminotransferase (AST) were measured pre, post, and 2 days after the marathon. CMJ and MIVC were reduced after the marathon (P < 0.05), but no group differences were observed (P > 0.05). Muscle soreness was increased in the day after the marathon (BTJ; 45 ± 48 vs. PLA; 46 ± 39 mm) and had returned to baseline by day 2, irrespective of supplementation (P = 0.694). Cytokines (interleukin-6; IL-6, interleukin-8, tumour necrosis factor-÷) were increased immediately post-marathon but apart from IL-6 had returned to baseline values by day 1 post. No interaction effects were evident for IL-6 (P = 0.213). Leucocytes increased 1.7-fold after the race and remained elevated 2 days post, irrespective of supplement (P < 0.0001). CK peaked at 1 day post marathon (BTJ: 965 ± 967, and PLA: 1141 ± 979 IU·L−1) and like AST and hs-CRP, was still elevated 2 days after the marathon (P < 0.05); however, no group differences were present for these variables. Beetroot juice did not attenuate inflammation or reduce muscle damage following a marathon, possibly because most of these indices were not markedly different from baseline values in the days after the marathon.
Author(s): Clifford T, Allerton DM, Brown MA, Harper L, Horsburgh S, Keane KM, Stevenson EJ, Howatson G
Publication type: Article
Publication status: Published
Journal: Applied Physiology, Nutrition and Metabolism
Print publication date: 01/03/2017
Online publication date: 09/11/2016
Acceptance date: 31/10/2016
Date deposited: 19/02/2018
ISSN (print): 1715-5312
ISSN (electronic): 1715-5320
Publisher: Canadian Science Publishing
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