Changes in free radical generation and antioxidant capacity during ultramarathon foot race

ABSTRACT Background Exhaustive exercise has been implicated in the generation of reactive oxygen species, resulting in oxidative stress. We studied the effect of a long‐distance, endurance exercise on oxidative stress parameters in athletes who participated in the ultramarathon race Spartathlon (246 km). Materials and methods This study included 18 runners (16 men and 2 women) aged 42·8 ± 1·4 years. Blood samples were obtained 24 h before (prerace), at the end (postrace) and 48 h after the end of the race (48 h postrace). We measured oxidative stress indices, including red cell glutathione, malonyldialdehyde and 8‐iso‐prostaglandin F2a, as well as the total antioxidant capacity. Results 8‐Iso‐prostaglandin F2a level increased significantly at the end of the race, compared to prerace levels (up to 914·7 ± 61·4 pg mL−1 from 197·6 ± 8·4 pg mL−1), and remained 2·5‐fold increased over the baseline 48 h after the race (532·0 ± 54·2 pg mL−1, P