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Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee and Song-Young Park

weight over a short period of time prior to competition. 4 This rapid weight change with high-intensity exercise training may result in the deterioration of the health and sports performance of these athletes, as it can lead to an abrupt disturbance of metabolism and increased oxidative stress, which

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Nathan A. Lewis, Andrew J. Simpkin, Sarah Moseley, Gareth Turner, Mark Homer, Ann Redgrave, Charles R. Pedlar and Richard Burden

-performance support team. Oxidative stress (OS), historically and simply defined as a disturbance in the prooxidant to antioxidant balance in favor of the former, 4 is evident in athletes diagnosed with overtraining syndrome 5 , 6 . Indeed, increases in biomarkers of OS correlate strongly with increases in training

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John Quindry, Lindsey Miller, Graham McGinnis, Megan Irwin, Charles Dumke, Meir Magal, N. Travis Triplett, Jeffrey McBride and Zea Urbiztondo

Acute strength exercise elicits a transient oxidative stress, but the factors underlying the magnitude of this response remain unknown. The purpose of this investigation was to determine whether muscle-fiber type relates to the magnitude of blood oxidative stress after eccentric muscle activity. Eleven college-age men performed 3 sets of 50 eccentric knee-extensions. Blood samples taken pre-, post-, and 24, 48, 72, and 96 hr postexercise were assayed for comparison of muscle damage and oxidative-stress biomarkers including protein carbonyls (PCs). Vastus lateralis muscle biopsies were assayed for relative percentage of slow- and fast-twitch muscle fibers. There was a mixed fiber composition (Type I = 39.6% ± 4.5%, Type IIa = 35.7% ± 3.5%, Type IIx = 24.8% ± 3.8%; p = .366). PCs were elevated 24, 48, and 72 hr (p = .032) postexercise, with a peak response of 126% (p = .012) above baseline, whereas other oxidative-stress biomarkers were unchanged. There are correlations between Type II muscle-fiber type and postexercise PC. Further study is needed to understand the mechanisms responsible for the observed fast-twitch muscle-fiber oxidative-stress relationship.

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John Quindry, Lindsey Miller, Graham McGinnis, Brian Kliszczewiscz, Dustin Slivka, Charles Dumke, John Cuddy and Brent Ruby

Previous research findings indicate that environmental temperature can influence exercise-induced oxidative-stress responses, although the response to variable temperatures is unknown. The purpose of this study was to investigate the effect of warm, cold, and “neutral,” or room, environmental temperatures on the blood oxidative stress associated with exercise and recovery. Participants (N = 12, age 27 ± 5 yr, VO2max = 56.7 ± 5.8 ml · kg-1 · min-1, maximal cycle power output = 300 ± 39 W) completed 3 exercise sessions consisting of a 1-hr ride at 60% Wmax, at 40% relative humidity in warm (33 °C), cold (7 °C), and room-temperature environments (20 °C) in a randomized crossover fashion. Rectal core temperature was monitored continually as participants remained in the respective trial temperature throughout a 3-hr recovery. Blood was collected preexercise and immediately, 1 hr, and 3 hr postexercise and analyzed for oxidative-stress markers including ferric-reducing ability of plasma (FRAP), Trolox-equivalent antioxidant capacity (TEAC), lipid hydroperoxides, and protein carbonyls. Core temperature was significantly elevated by all exercise trials, but recovery core temperatures reflected the given environment. FRAP (p < .001), TEAC (p < .001), and lipid hydroperoxides (p < .001) were elevated after warm exercise while protein carbonyls were not altered (p > .05). These findings indicate that moderate-intensity exercise and associated recovery in a warm environment elicits a blood oxidative-stress response not observed at comparable exercise performed at lower temperatures.

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Lindsey E. Miller, Graham R. McGinnis, Brian Kliszczewicz, Dustin Slivka, Walter Hailes, John Cuddy, Charles Dumke, Brent Ruby and John C. Quindry

Oxidative stress occurs as a result of altitude-induced hypobaric hypoxia and physical exercise. The effect of exercise on oxidative stress under hypobaric hypoxia is not well understood.

Purpose:

To determine the effect of high-altitude exercise on blood oxidative stress. Nine male participants completed a 2-d trek up and down Mt Rainer, in North America, at a peak altitude of 4,393 m. Day 1 consisted of steady-pace climbing for 6.25 hr to a final elevation of 3,000 m. The 4,393-m summit was reached on Day 2 in approximately 5 hr. Climb–rest intervals varied but were consistent between participants, with approximately 14 hr of total time including rest periods. Blood samples were assayed for biomarkers of oxidative stress and antioxidant potential at the following time points: Pre (before the trek), 3Kup (at ascent to 3,000 m), 3Kdown (at 3,000 m on the descent), and Post (posttrek at base elevation). Blood serum variables included ferric-reducing antioxidant potential (FRAP), Trolox equivalent antioxidant capacity (TEAC), protein carbonyls (PC), and lipid hydroperoxides. Serum FRAP was elevated at 3Kup and 3Kdown compared with Pre and Post values (p = .004, 8% and 11% increase from Pre). Serum TEAC values were increased at 3Kdown and Post (p = .032, 10% and 18% increase from Pre). Serum PC were elevated at 3Kup and 3Kdown time points (p = .034, 194% and 138% increase from Pre), while lipid hydroperoxides were elevated Post only (p = .004, 257% increase from Pre).

Conclusions:

Findings indicate that high-altitude trekking is associated with increased blood oxidative stress.

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Andrew W. Subudhi, Scott L. Davis, Ronald W. Kipp and E. Wayne Askew

The goal of this field study was to assess antioxidant status and markers of oxidative damage in elite alpine ski racers during routine training. Subjects included 12 members of the U.S. Men’s Alpine Ski Team attending a 10-day summer training camp. Blood draws were collected at rest and after exercise: (a) prior to training, (b) following 2 days of dry land training, and (c) after 4 days of on-snow skiing. Seven measures of antioxidant status were determined using colorimetric and HPLC methods (Trolox “equivalent antioxidant capacity, uric acid, α-tocopherol, β-tocopherol, total glutathione, cytosolic glutathione peroxidase, and superoxide dismutase). Oxidative stress was assessed using 2 markers of lipid peroxidation (malondialdehyde and lipid hydroperoxides) and 2 markers of protein oxidation (carbonylated total proteins and carbonylated hemoglobin). The results of this study suggest that antioxidant status of elite alpine skiers may decline over a period of intense training. However, elevations in markers of oxidative stress were not evident.

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Trent A. Watson, Lesley K. MacDonald-Wicks and Manohar L. Garg

Exercise has been shown to increase the production of reactive oxygen species to a point that can exceed antioxidant defenses to cause oxidative stress. Dietary intake of antioxidants, physical activity levels, various antioxidants and oxidative stress markers were examined in 20 exercise-trained “athletes” and 20 age- and sex-matched sedentary “controls.” Plasma F2-isoprostanes, antioxidant enzyme activities, and uric acid levels were similar in athletes and sedentary controls. Plasma α-tocopherol and β-carotene were higher in athletes compared with sedentary controls. Total antioxidant capacity tended to be lower in athletes, with a significant difference between male athletes and male controls. Dietary intakes of antioxidants were also similar between groups and well above recommended dietary intakes for Australians. These findings suggest that athletes who consume a diet rich in antioxidants have elevated plasma α-tocopherol and β-carotene that were likely to be brought about by adaptive processes resulting from regular exercise.

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Graham McGinnis, Brian Kliszczewiscz, Matthew Barberio, Christopher Ballmann, Bridget Peters, Dustin Slivka, Charles Dumke, John Cuddy, Walter Hailes, Brent Ruby and John Quindry

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 VO2peak performed in a normoxic environment (normoxic intensity-normoxic environment, NI-NE), 60% hypoxic VO2peak performed in a normoxic environment (HI-NE), and 60% hypoxic VO2peak 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 VO2peak 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.

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David C. Nieman, Courtney L. Capps, Christopher R. Capps, Zack L. Shue and Jennifer E. McBride

useful in attenuating oxidative stress and inflammation induced by acute and chronic prolonged and intensive exercise training ( Harms-Ringdahl et al., 2012 ; Samaras et al., 2014 ; Tsitsimpikou et al., 2013 ). For example, lycopene supplementation for 30 days protected rat muscle tissue from oxidative

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Alfredo Córdova, Antoni Sureda, María L. Albina, Victoria Linares, Montse Bellés and Domènec J. Sánchez

The aim was to determine the levels and activities of the oxidative stress markers in erythrocytes, plasma, and urine after a flat cyclist stage. Eight voluntary male professional trained-cyclists participated in the study. Exercise significantly increased erythrocyte, leukocyte, platelet, and reticulocyte counts. The exercise induced significant increases in the erythrocyte activities of catalase (19.8%) and glutathione reductase (19.2%), while glutathione peroxidase activity decreased significantly (29.3%). Erythrocyte GSSG concentration was significantly increased after exercise (21.4%), whereas GSH was significantly diminished (20.4%). Erythrocyte malondialdehyde levels evidenced a significant decrease 3 h after finishing the stage (44.3%). Plasma malondialdehyde, GSH and GSSG levels significantly decreased after 3 hr recovery (26.8%, 48.6%, and 31.1%, respectively). The exercise significantly increased the F2-isoprostane concentration in urine from 359 ± 71 pg/mg creatinine to 686 ± 139 pg/mg creatinine. In conclusion, a flat cycling stage induced changes in oxidative stress markers in erythrocytes, plasma, and urine of professional cyclists. Urine F2-isoprostane is a more useful biomarker for assessing the effects of acute exercise than the traditional malondialdehyde measurement.