Minimal muscle damage after a marathon and no influence of beetroot juice on inflammation and recovery.
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-α) 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.
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Tom
T
Clifford
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Dean M
DM
Allerton
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Meghan A
MA
Brown
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Liam
L
Harper
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Steven
S
Horsburgh
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.
Karen M
KM
Keane
b Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Newcastle NE1 7RU, UK.
Emma J
EJ
Stevenson
a Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle NE1 8ST, UK.|c Water Research Group, School of Environmental Sciences and Development, Northwest University, Potchefstroom 2520, South Africa.
Glyn
G
Howatson
D000328:Adult; D027461:Beta vulgaris; D002097:C-Reactive Protein / Q000378:metabolism; D003402:Creatine Kinase / Q000097:blood; D016207:Cytokines / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004311:Double-Blind Method; D002149:Energy Intake; D005260:Female; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000178:diet therapy*; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D063806:Myalgia / Q000097:blood / Q000178:diet therapy*; D019707:Receptors, Chemokine / Q000097:blood; D012420:Running
D016207:Cytokines; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D019707:Receptors, Chemokine; D002097:C-Reactive Protein; D003402:Creatine Kinase
aliments fonctionnels; betalains; bétalaïnes; course; exercise recovery; fonction neuromusculaire; functional foods; marathon; neuromuscular function; running; récupération post-exercice