Acute Hypoxia and Exercise-Induced Blond Oxidative Stress

作者：McGinnis Graham; Kliszczewiscz Brian; Barberio Matthew; Ballmann Christopher; Peters Bridget; Slivka Dustin; Dumke Charles; Cuddy John; Hailes Walter; Ruby Brent; Quindry John^*

来源：International Journal of Sport Nutrition and Exercise Metabolism, 2014, 24(6): 684-693.

DOI：10.1123/ijsnem.2013-0188

• cycling exercise
• altitude
• reactive oxygen species
• environmental physiology

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 %26lt;= .05. Oxygen saturation during the HI-HE trial was lower than NI-NE and HI-NE (p %26lt; .05). A Time x 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.

• 出版日期2014-12