Thèse soutenue

Stress oxydatif, exercice de sprint et lactate
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Accès à la thèse
Auteur / Autrice : Carole Groussard
Direction : Arlette Delamarche
Type : Thèse de doctorat
Discipline(s) : Sciences de la vie. Sciences et techniques des activités physiques et sportives
Date : Soutenance en 2001
Etablissement(s) : Rennes 2

Mots clés

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Résumé

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Numerous studies over the past few decades have demonstrated that aerobic exercise, if strenuous enough, induces an oxidative stress. Several factors may be involved in this free radical generation during aerobic exercise but the most important during such exercise is the important increase in oxygen consumption. Yet the effects of sprint anaerobic exercise on oxidative stress markers have not been fully clarified. Few studies have investigated this hypothesis and the existing data in humans are conflicting. Thus, the main purpose of this study was to detect an oxidative stress in human blood after a very brief and intense cycle-sprint exercise (the Wingate test) by measuring plasma lipid peroxidation markers (serum lipid radicals detected by ESR spectroscopy and plasma TBARS) and blood antioxidant system (SOD, GPx, GSH, uric acid and vitamin status). Lactate effect on free radical production and dietary antioxidant intake on oxidative stress induced by acute or chronic exercise will also be examinate. This study indicates that sprint anaerobic exercise increases lipid radical production and alteres the antioxidant status. However plasma TBARS is not a suitable marker in such exercise. Moreover, this study provides evidences that lactate ion, which is produced in a great amount during sprint exercise, may act as a good antioxydant. In vitro, it has been demonstrated to directly scavenge O2°- and °OH. Analysis of the daily antioxidant vitamin intake indicates a deficiency in antioxidant vitamin intake. This deficiency may be one explanation for the low plasma non-enzymatic antioxydant status observed at rest and may contribute to the alteration in plasma non-enzymatic antioxidant status in response to acute exercise. Finally, it seems that a low plasma non-enzymatic antioxidant status at rest increases the risk of chronic oxidative stress at rest, expecially in subjects who exibit a high phisical fitness level.