Oxidative stress and antioxidant changes during a 24-hours mountain bike endurance exercise in master athletes.

Aim. This work monitored changes in oxidative stress and antioxidant defence during an endurance exercise in over 40 years old athletes. Methods. Subjects were monitored during the 24-hours mountain bike Idro Lake (North of Italy) competition which took place in June 2008. The race lasted for 24 h, starting at 10.00 a.m., ending at 10.00 a.m. of the following day and was based upon riding for as many kilometers as possible in the 24-hours time schedule in a 5.5 km circuit trail. The study included 6 men bikers, aged 44.8 ± 2 years, who raced on an individual basis. Blood samples were collected and the oxidative stress was measured performing the d-ROMs test which determined the reactive oxygen metabolites (ROMs), whereas the antioxidant defence status was assessed determining the biological antioxidant potential (BAP test). Results. The ROMs levels significantly increased after 8 h from the beginning of the competition (122 %), at the end of the race (162%), 24 h (158%) and 48 h (144%) post-race. The biological antioxidant potential significantly increased at the end of the race (128%) and remained elevated 48 h later (114%). After 72 h post-race, ROMs and BAP levels differed significantly amongst subjects, thus showing an individual response to oxidative stress. Conclusion. In conclusion, exposure to intense and prolonged exercise induced a marked increase in dROMs levels in master athletes, only partially counterbalanced by antioxidants in blood plasma. The long-term effects of oxidative agents on the human body requires further studies, but it is likely that a diet potentially rich in antioxidants would help preventing oxidative damage of body cells and tissues and enhancing recovering from the endurance performance.