Antioxidant status, oxidative stress, and damage in elite kayakers after 1 year of training and competition in 2 seasons.
The large volume of training performed by elite athletes throughout the season can translate into a chronic oxidative insult. To study the effects that chronically high training loads have on athletes' redox status, superoxide dismutase (SOD), glutathione reductase, glutathione peroxidase (GPx), and creatine kinase activities; total antioxidant status (TAS); and uric acid, retinol, alpha-tocopherol, alpha-carotene, beta-carotene, lycopene, lutein + zeaxanthin, vitamin C, thiobarbituric acid reactive substances (TBARS), interleukin-6, and cortisol levels were determined in 9 kayakers (6 men) in a competitive period during the first season (June, T1), and in precompetitive (March, T2) and competitive (June, T3) periods during the following season. TAS decreased from the first to the second season (T1 vs. T2, p < 0.001; T1 vs. T3, p < 0.001). TBARS (p = 0.024) decreased from T1 to T2. The alpha-tocopherol increase (p = 0.001) from T1 to T2 lost statistical significance after adjustment for total lipids (p = 0.243). GPx (p = 0.003) increased, while SOD (p < 0.001) and uric acid (p = 0.032) decreased from T2 to T3. Cortisol levels decreased significantly throughout the study (T1 vs. T2, p = 0.042; T2 vs. T3, p = 0.018; T1 vs. T3, p = 0.002). No significant differences were observed for any of the other parameters studied. Antioxidant status changed more within the same season than from one season to another. Redox markers should be monitored throughout the season to detect athletes at an increased oxidative risk.
Teixeira
Vitor
V
Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal. vhugoteixeira@fcna.up.pt
Valente
Hugo
H
Casal
Susana
S
Pereira
Laura
L
Marques
Franklim
F
Moreira
Pedro
P
D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D052283:Creatine Kinase, MM Form / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D018836:Inflammation Mediators / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D015227:Lipid Peroxidation; D008137:Longitudinal Studies; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009135:Muscular Diseases / Q000378:metabolism* / Q000473:pathology; D009752:Nutritional Status; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D000975:Antioxidants; D015415:Biomarkers; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D052283:Creatine Kinase, MM Form; D006854:Hydrocortisone