Impact of ironman triathlon on oxidative stress parameters Impacto do triatlon ironman sobre os parametros de estresse oxidativo

1 Abstract - Several studies have investigated the biochemical response changes that take place in Ironman triathletes, but there are few data on oxidative stress changes. The ob- jective of this study was to investigate oxidative stress parameters in triathletes after an Ironman event. The sample consisted of eighteen male triathletes, with a mean age of 34.5 ± 2.15 years, weight 69.3 ± 1.9 kg, and height 1.71 ± 0.18 m. The Ironman triathlon consists of a 3.8-km swim, a 180-km bicycle ride, and a 42.2-km (marathon) run. Before the competition and immediately after its conclusion, 10-mL blood samples were collected, centrifuged and frozen at -80oC for subsequent analysis. Total antioxidant capacity, lipid peroxidation, protein carbonylation, and total thiol content were measured. The results showed a significant increase in all markers after the event (p<0.05) in relation to the pre- -event period, which conclusively shows that the Ironman triathlon induces significant changes oxidative stress markers in athletes and that antioxidant supplementation would be important to reverse these effects.