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Steven R. McAnulty, Lisa S. McAnulty, Jason D. Morrow, David C. Nieman, John T. Owens and Cristin M. Carper

This study compared effects of carbohydrate (CHO) and rest on oxidative stress during exercise. Cyclists (N = 12) completed 4 randomized trials at 64% Wattsmax under 2 conditions (continuous cycling for 2 h [C] and cycling with 3-min rest every 10 min for 2.6 h [R]). Subjects cycled under each condition while receiving 6% CHO and placebo (PLA). CHO and PLA were given pre exercise (12 mL/kg) and during exercise (4 mL·kg−1·15 min−1). Blood was collected pre exercise, post exercise, and 1 h post exercise and assayed for F2-isoprostanes, hydroperoxides (LH), nitrite, antioxidant capacity, glucose, insulin, cortisol, and epinephrine. F2-isoprostanes and LH were lower in CHO. Glucose, cortisol, and epinephrine exhibited significant effects, with post exercise levels of glucose higher and cortisol and epinephrine lower in CHO during the R condition. This pattern was identical in the C condition (21). Oxidative stress during cycling was unaffected by use of short rest intervals but was diminished by CHO.

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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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Anna Skarpañska-Stejnborn, Lucia Pilaczynska-Szczesniak, Piotr Basta, Ewa Deskur-Smielecka and Magorzata Horoszkiewicz-Hassan

High-intensity physical exercise decreases intracellular antioxidant potential. An enhanced antioxidant defense system is desirable in people subjected to exhaustive exercise. The aim of this study was to investigate the influence of supplementation with artichoke-leaf extract on parameters describing balance between oxidants and antioxidants in competitive rowers. This double-blinded study was carried out in 22 members of the Polish rowing team who were randomly assigned to a supplemented group (n = 12), receiving 1 gelatin capsule containing 400 mg of artichoke-leaf extract 3 times a day for 5 wk, or a placebo group (n = 10). At the beginning and end of the study participants performed a 2,000-m maximal test on a rowing ergometer. Before each exercise test, 1 min after the test completion, and after a 24-hr restitution period blood samples were taken from antecubital vein. The following redox parameters were assessed in red blood cells: superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione levels, and thiobarbituric-acid-reactive-substances concentrations. Creatine kinase activity and total antioxidant capacity (TAC) were measured in plasma samples, lactate levels were determined in capillary blood samples, and serum lipid profiles were assessed. During restitution, plasma TAC was significantly higher (p < .05) in the supplemented group than in the placebo group. Serum total cholesterol levels at the end of the study were significantly (p < .05) lower in the supplemented group than in the placebo group. In conclusion, consuming artichoke-leaf extract, a natural vegetable preparation of high antioxidant potential, resulted in higher plasma TAC than placebo but did not limit oxidative damage to erythrocytes in competitive rowers subjected to strenuous training.

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Gabriella Berwig Möller, Maria Júlia Vieira da Cunha Goulart, Bruna Bellincanta Nicoletto, Fernanda Donner Alves and Cláudia Dornelles Schneider

metabolites and biological antioxidant potential) Less increment in reactive oxygen metabolites ( p  < .05) and higher biological antioxidant potential after exercise in probiotic group ( p  < .01), indicating high antioxidant activity during exercise Ultramarathon runners N  = 32—26 M/6 F Age 23–53 years

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David C. Nieman, Courtney L. Goodman, Christopher R. Capps, Zack L. Shue and Robert Arnot

 minutes and then centrifuged at 12,000 g for 10 min at 4 °C. The supernatant of each tube was transferred to an autosampler vial for LC-MS analysis. Plasma FRAP Analysis Total plasma antioxidant potential/capacity was determined by the ferric reducing ability of plasma (FRAP) assay as previously described

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

-density lipoproteins (oxLDLs) in human plasma were determined using a quantitative direct sandwich enzyme-linked immunosorbent assay kits provided by Mercodia (Uppsala, Sweden). Total plasma antioxidant potential/capacity was determined by the ferric reducing ability of plasma (FRAP) assay, a single-electron transfer