Extreme running competition decreases blood antioxidant defense capacity.
OBJECTIVE
We tested whether an extreme running competition ("Marathon of Sands") might alter the blood's enzymatic and non-enzymatic antioxidant status in 6 well-trained athletes.


METHODS
The Marathon of Sands is a competition consisting of six long duration races in the desert in which the athletes carry their own food. Blood samples were collected from an antecubital vein while the athletes were at rest before the competition and then again 72 hours after. Erythrocyte antioxidant enzyme activity (glutathione peroxidase, superoxide dismutase), erythrocyte glutathione level, plasma non-enzymatic status (vitamin C, alpha-tocopherol, retinol, beta-carotene and carotenoids) and plasma lipid peroxidation marker (TBARS) were measured.


RESULTS
The Marathon of Sands induced a significant alteration of the blood antioxidant defense capacity. Indeed, 72 hours after the race, significant decreases were recorded in erythrocyte superoxide dismutase activity and in plasma concentrations of retinol, beta-carotene and other carotenoids. These changes were associated with a concomitant increase in erythrocyte glutathione and in plasma TBARS levels.


CONCLUSIONS
This study indicated that such extreme competition induced an imbalance between oxidant and antioxidant protection.
Laboratoire de Physiologie et de Biomécanique de l'Exercice Musculaire, UFRAPS Université de Rennes 2, EA 1274, Avenue Charles Tillon, Campus la Harpe, CS 24414, 35044 Rennes Cedex, France.
Guillaume
G
Machefer
Carole
C
Groussard
Françoise
F
Rannou-Bekono
Hassane
H
Zouhal
Henry
H
Faure
Sophie
S
Vincent
Josiane
J
Cillard
Arlette
A
Gratas-Delamarche
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D014801:Vitamin A / Q000097:blood
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D014801:Vitamin A; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid