@article{5ad5385f48aa416fab29274006cb71dd,
title = "Antioxidant Supplementation Protects Elite Athlete Muscle Integrity During Submaximal Training",
abstract = "Purpose: To determine (1) the effect of a 40-minute steady-state run on muscle membrane integrity of elite athletes as reflected by serum creatine kinase (CK), (2) whether antioxidant supplementation (AS) with vitamins E and C has a protective effect, and (3) if a minimal blood concentration of vitamin E or C is required for any such protection. Methods: Fifteen elite-level endurance athletes (V O2max = 71.5 ± 1.2 mL kg-1 min-1) were randomly assigned to 6 weeks AS (1000 IU d-1 natural vitamin E and 1000 mg d-1 vitamin C) or placebo. Using a double-blind crossover design and 4-week washout period, each treatment was followed by a 40-minute steady-state run at 3 mM blood lactate. Blood samples before and 0 and 24 hours after the run were assayed for serum and red cell α-tocopherol (α-TOH), serum ascorbate, and CK. Results: The AS produced a 2.5-fold, wellcorrelated (r = .84) increase in serum and red cell α-TOH (P < .001) that attenuated the increase in postrun CK (P = .01). There was no change in serum ascorbate with AS and no relationship with CK (P > .1). Curvilinear regression revealed some evidence that a critical level of serum α-TOH in the vicinity of 12 mg L-1 was required to attenuate CK efflux, a level only achieved with AS. Conclusion: The muscle membrane integrity of elite-level athletes is compromised even during steady-state running of moderate intensity and duration. The AS provided a protective effect, with evidence that a serum α-TOH concentration of around 12 mg L-1 is required.",
keywords = "endurance athletes, muscle membrane integrity, submaximal running, vitamin C, vitamin E",
author = "Gillam, {Ian H.} and Cunningham, {Ross B.} and Telford, {Richard D.}",
note = "Funding Information: Author I.G. was awarded a research fellowship from the Department of Physiology and Applied Nutrition at Australian Institute of Sport to conduct this project. Natural vitamin E was provided by gift for the study from the Henkel Corp, La Grange, IL, and the antioxidant supplement and PL supplements used in this study were manufactured by RP Scherer Pty Ltd, Melbourne, Australia. The Henkel Corp and RP Scherer had no influence on the design, biochemical, or statistical analyses or inferences on the interpretation or reporting of the study. The corresponding author confirms that he had full access to all the data included in the published manuscript. The authors wish to acknowledge support from Dr Sandiford Skinner at the University of Melbourne for his assistance with the design of the study and advice in the interpretation of the data. Dr Maurie Weidemann provided ongoing advice, and the Department of Biochemistry at the ANU, Canberra, ACT provided laboratory space and equipment to conduct the some of the biochemical analyses. Dr Roland Stocker, Department of Biochemistry, ANU also provided his advice on the biochemical analyses used and for conducting the serum vitamin C assays in this study. The authors thank Ms Sarah Dacres-Manning and Dr Louise Burke, Department of Sports Nutrition at the Australian Institute of Sport for undertaking the dietary analyses. The authors thank the athletes who agreed to participate and devote their time and commitment to undertake this study. Publisher Copyright: {\textcopyright} 2022 Human Kinetics Publishers Inc.. All rights reserved.",
year = "2022",
month = apr,
doi = "10.1123/ijspp.2021-0051",
language = "English",
volume = "17",
pages = "549--555",
journal = "International Journal of Sports Physiology and Performance",
issn = "1555-0265",
publisher = "Human Kinetics Publishers Inc.",
number = "4",
}