The oxidative stress in response to routine incremental cycling exercise in healthy sedentary subjects.

The kinetics of blood markers of the oxidative stress during and after an incremental exercise until the maximal performances is not documented in healthy sedentary subjects. We studied subjects of both sexes cycling on an ergometer until or near the V(O)(2)(max) measurement, and we measured during exercise and a 30-min recovery period the plasma concentration of thiobarbituric acid reactive substances (TBARS) which explored the production of reactive oxygen species (ROS) and two antioxidants (plasma reduced ascorbic acid (RAA) and erythrocyte reduced glutathione (GSH)). Despite we noted inter-individual differences in the instants of maximal variations of TBARS, GSH, and RAA, they were all measured within the first 20 min of the post-exercise recovery period, and at the 30th min of recovery, the three ROS blood markers tended to recover their pre-exercise levels. The maximal TBARS increase was positively correlated with V(O)(2)(max) and negatively correlated with the magnitude of RAA consumption. Our results indicate the existence of an early post-exercise oxidative stress in healthy sedentary volunteers. They also show that the ROS production is proportional to the maximal aerobic power and inversely related to the consumption of plasma antioxidants.