Abstract
The longitudinal monitoring of oxidative stress (OS) in athletes may enable the identification of fatigued states and underperformance. The application of OS biomarker monitoring programs in sport are hindered by reliability and repeatability of in-the-field testing tools, the turnaround of results, and the understanding of biological variation (BV). Knowledge of BV and critical difference values (CDV) may assist with data interpretation in the individual athlete. Methods: We aimed firstly to assess the repeatability of the clinical point of care redox test, Free Oxygen Radical Test (FORT) and the Free Oxygen Radical Defence (FORD) in trained participants and elite athletes and secondly to calculate the analytical, BV, CDV and index of individuality (II) for FORT, FORD, red blood cell glutathione, lutein, α and γ–tocopherol. Part 1: Fifteen elite athletes were sampled in duplicate for calculation of the repeatability of the FORT and FORD tests. Part 2: Twelve well-trained athletes had venous samples drawn every 2 hours from 0800 to 1800 for calculation of BV, CDV, II for FORT, FORD, RBC GSH, lutein, α-tocopherol and γ–tocopherol. Results: Repeatability of the FORT and FORD assay was 3.9% and 3.7% respectively. Biomarker CDV ranged from 12.8% to 37%, with a circadian effect for FORT, α-tocopherol and γ-tocopherol (p<0.01), with all biomarker indices of individuality < 0.8 arbitrary units. Conclusion: We report that the use of the novel redox test in athletes is practical, and the generation of BV and CDV for biomarkers of OS enhances the interpretation of physiologically meaningful changes in individuals above the use of clinical reference ranges alone.
Highlights
Exercise results in the production of reactive nitrogen and oxygen species (RNOS) and oxidative stress (OS), an effect observed after all types of exercise and consistent across species, and in different cell types, body fluids and tissues [1,2]
There was no effect for time for lutein (p = 0.60), RBC GSH (p = 0.52) and Free Oxygen Radical Defence (FORD) (p = 0.26)
We provide evidence of a significant circadian effect for Free Oxygen Radical Test (FORT), and serum α and γ-tocopherol; no effect was observed for the antioxidants lutein, FORD or RBC GSH
Summary
Exercise results in the production of reactive nitrogen and oxygen species (RNOS) and oxidative stress (OS), an effect observed after all types of exercise and consistent across species, and in different cell types, body fluids and tissues [1,2]. Exercise training increases endogenous antioxidant enzymes along with biomarkers of cell lipid and protein oxidation, with changes proportional to training volume and load [1,7,8]. The successful application of OS biomarker monitoring programs in elite sport is hindered by: 1) repeatability of in-the-field testing tools and the need for rapid turnaround of results; 2) an understanding of the athletes’ individual biological variation (BV) to elucidate meaningful changes [1,9] and 3) the inherent costs of the analytical methods and the invasive nature of repeated venous sampling. The monitoring of OS, with a point of care (POC) test, coupled with knowledge of the specific BV may assist practitioners with exercise prescription, recovery modalities and dietary interventions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
