NO EVIDENCE OF OXIDATIVE STRESS AFTER A TRIATHLON RACE IN HIGHLY TRAINED COMPETITORS

Long distance triathlons, due to the large amounts of oxygen uptake th ey cause, may lead to the generation of reactive oxygen species, and c onsequently to oxidative stress and damage. We sought to verify this h ypothesis. Twelve of the 18 male triathletes who participated in the s tudy took part in a long distance triathlon, the others did not. The p rerace blood samples were drawn 48 h before the race and repeatedly un til the fourth day of recovery. The myoglobin concentrations increased immediately after the race. The concentrations of methemoglobin, disu lfide glutathione (GSSG), and thiobarbituric reactive substances did n ot significantly change after the race. Although the race induced an i nflammatory response, evidenced by the variations in neopterin concent rations and leukocyte counts, there was no consecutive oxidative stres s. The basal GSH values were correlated significantly with cycling tra ining volume (r = 0.55) and (V) over dot(2)max (r = 0.53). Muscle dama ge can occur without evidence of oxidative stress or oxidative damage. We conclude that the magnitude of the antioxidant defense system enha ncement depends on training loads. Because of their training status, t he triathletes did not suffer from oxidative damage after they finishe d the long distance triathlon race.