title: Acute hypoxia and exercise-induced blood oxidative stress.
abstract: Hypoxic exercise is characterized by workloads decrements. Because exercise and high altitude independently elicit redox perturbations, the study purpose was to examine hypoxic and normoxic steady-state exercise on blood oxidative stress. Active males (n = 11) completed graded cycle ergometry in normoxic (975 m) and hypoxic (3,000 m) simulated environments before programing subsequent matched intensity or workload steady-state trials. In a randomized counterbalanced crossover design, participants completed three 60-min exercise bouts to investigate the effects of hypoxia and exercise intensity on blood oxidative stress. Exercise conditions were paired as such; 60% normoxic VO(2)peak performed in a normoxic environment (normoxic intensity-normoxic environment, NI-NE), 60% hypoxic VO(2)peak performed in a normoxic environment (HI-NE), and 60% hypoxic VO(2)peak performed in a hypoxic environment (HI-HE). Blood plasma samples drawn pre (Pre), 0 (Post), 2 (2HR) and 4 (4HR) hr post exercise were analyzed for oxidative stress biomarkers including ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), lipid hydroperoxides (LOOH) and protein carbonyls (PCs). Repeated-measures ANOVA were performed, a priori significance of p ≤ .05. Oxygen saturation during the HI-HE trial was lower than NI-NE and HI-NE (p < .05). A Time × Trial interaction was present for LOOH (p = .013). In the HI-HE trial, LOOH were elevated for all time points post while PC (time; p = .001) decreased post exercise. As evidenced by the decrease in absolute workload during hypoxic VO(2)peak and LOOH increased during HI-HE versus normoxic exercise of equal absolute (HI-NE) and relative (NI-NE) intensities. Results suggest acute hypoxia elicits work decrements associated with post exercise oxidative stress.
authors.affiliation: School of Kinesiology, Auburn University, Auburn AL.
authors.forename: Graham
authors.initials: G
authors.lastname: McGinnis
authors.forename: Brian
authors.initials: B
authors.lastname: Kliszczewiscz
authors.forename: Matthew
authors.initials: M
authors.lastname: Barberio
authors.forename: Christopher
authors.initials: C
authors.lastname: Ballmann
authors.forename: Bridget
authors.initials: B
authors.lastname: Peters
authors.forename: Dustin
authors.initials: D
authors.lastname: Slivka
authors.forename: Charles
authors.initials: C
authors.lastname: Dumke
authors.forename: John
authors.initials: J
authors.lastname: Cuddy
authors.forename: Walter
authors.initials: W
authors.lastname: Hailes
authors.forename: Brent
authors.initials: B
authors.lastname: Ruby
authors.forename: John
authors.initials: J
authors.lastname: Quindry
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D054874:Athletic Performance / Q000502:physiology; D002839:Chromans / Q000097:blood; D018592:Cross-Over Studies; D004777:Environment; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005290:Ferric Compounds / Q000097:blood; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D050050:Protein Carbonylation / Q000502:physiology; D055815:Young Adult
chemical_list: D000975:Antioxidants; D002839:Chromans; D005290:Ferric Compounds; D008054:Lipid Peroxides; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid