Effects of acute hypoxic exposure on prooxidant/antioxidant balance in elite endurance athletes.
We investigated whether acute hypoxic exposures could modify the pro-oxidant/antioxidant balance in elite endurance athletes, known to have efficient antioxidant status. Forty-one elite athletes were subjected to two hypoxic tests: one at an altitude of 4 800 m during 10-min of mild exercise (4 800 m test) and the second at rest for 3 h at an altitude of 3 000 m (3 000 m test). Plasma levels of advanced oxidation protein products (AOPP), malondialdehydes (MDA), ferric reducing antioxidant power (FRAP) and lipid-soluble antioxidants were measured before and immediately after the 4 800 m test and at the end of the 3 000 m test. The 4 800 m and the 3 000 m tests induced a significant increase in the level of MDA and AOPP (+7.1% and +71.7% for 4 800 m test and +8.6% and +40.9% for 3 000 m test). The changes in plasma MDA and arterial oxygen saturations were significantly correlated (r=0.35) during the 3 000 m test. FRAP values (-13%) and alpha-tocopherol (-21%) were decreased following the 3 000 m test. However, following the 4 800 m test, only alpha-tocopherol was decreased (-16%). These results provide evidence that the highly-trained athletes do not have the antioxidant buffering capacity to counterbalance free radical over-production generated by acute hypoxic exposure, with or without mild exercise.
Pialoux
V
V
Laboratoire de Biologie des Activités Physiques et Sportives, Facultè de Médecine, Clermont-Ferrand, France. pialouxvincent@yahoo.fr
Mounier
R
R
Rock
E
E
Mazur
A
A
Schmitt
L
L
Richalet
J-P
JP
Robach
P
P
Coudert
J
J
Fellmann
N
N
D000208:Acute Disease; D000328:Adult; D000531:Altitude; D000704:Analysis of Variance; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers; D017079:Exercise Tolerance; D005260:Female; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D000860:Hypoxia / Q000150:complications* / Q000503:physiopathology; D008297:Male; D018384:Oxidative Stress; D010101:Oxygen Consumption; D017382:Reactive Oxygen Species / Q000378:metabolism*; D055815:Young Adult; D024502:alpha-Tocopherol / Q000378:metabolism
D000975:Antioxidants; D015415:Biomarkers; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D024502:alpha-Tocopherol