@article{ccedfb72af4f46bb8265ab59792a8538,
title = "Exercise-induced oxidative stress in overload training and tapering",
abstract = "Tapering can be an effective way of enhancing performance after a period of intensive training, but the mechanisms for this ergogenic effect are unclear. It was hypothesized that overload training will increase oxidative stress through an accumulative effect of repeated high-intensity exercise, whereas tapering will improve the antioxidant defense system and alleviate oxidative stress. Purpose: To study the oxidative stress response to overload training and tapering. Methods: A group of eight well-trained male endurance athletes (30 ± 6yr; 73 ± 13 kg; 64 ± 6 mL·kg -1·min-1<![CDATA[) performed two 4-wk periods of training in a crossover design. Each period included a 2-wk build-up phase followed either by 2 wk of training at the same load (control) or by a week with a 40% increase in training load (overload) preceding a week with a 60% reduction in training load (taper). Performance was monitored through weekly 15-min cycling time trials preceded by a 45-min preload at 70% Wmax. Blood samples were taken before and after the time trials and analyzed for oxidatively modified heme (OxHm), methemoglobin (metHb), and glutathione redox status. Results: Cycling time trials induced significant postexercise increases in levels of OxHm (+3.8%; P < 0.001) and oxidized glutathione (GSSG: +13.9%; P < 0.05) and decreases in metHb (-12.1%; P < 0.001), reduced glutathione (GSH: -14.4%; P < 0.001), and GSH/GSSG (-29.7%; P < 0.001). Tapering was shown to significantly increase performance (+4.9%; P < 0.05). Training modifications did not influence resting levels or exercise-induced changes of markers of oxidative stress. Conclusion: A short period of tapered training improves performance but does not seem to be associated with substantial changes in exercise-induced oxidative stress. Copyright {\textcopyright} 2006 by the American College of Sports Medicine.]]>",
keywords = "Antioxidants, Exercise performance, Free radicals, Glutathione, Oxidatively modified heme",
author = "Vollaard, {N. B J} and Cooper, {Chris E.} and Shearman, {Jerry P.}",
year = "2006",
month = jul,
doi = "10.1249/01.mss.0000227320.23847.80",
language = "English",
volume = "38",
pages = "1335--1341",
journal = "Medicine and Science in Sports and Exercise",
issn = "0195-9131",
publisher = "Lippincott, Williams and Wilkins",
number = "7",
}