Regular physical exercise prevents nitrosative stress caused by ageing in elderly athletes

Ageing is associated with an increased susceptibility to free radical-induced tissue damage. One of the most important classes of free radicals generated in living systems is represented by reactive nitrogen species (RNS), responsible for the so-called nitrosative stress. It has been shown that physical activity is able to induce up-regulation of antioxidant systems contributing to prevent oxidative stress. The aim of the present study was to assess whether regular physical activity is able to counteract age-induced nitrosative stress. Thirty male endurance athletes (average age 70.8 ± 6.1 years, VO2max 59.07 ± 8.5 ml/kg/min) and thirty age-sex-matched sedentary controls ( average age 71.5 ± 4.3 years, VO2max 25.6 ± 8.2 ml/kg/min) were studied. Plasma free radicals antioxidant capacity against peroxynitrite, one of the most important RNS, was evaluated as Total Oxyradical Scavenging Capacity (TOSC) units. Results. Plasma TOSC values against peroxynitrite were higher in athletes than in sedentary controls (22.94 ± 1.85 vs 15.41 ± 1.24 units/ml, p < 0.001). In the athletes group, TOSC values were related to VO2max (r = 0.44, p < 0.05). In conclusion, these results suggest that regular physical activity is associated with increased antioxidant defences in elderly athletes. In athletes, a direct correlation between the scavenger scavenger of the plasma and the VO2max (r = 0.44, p <0.05) was also observed. These results confirm that regular physical activity practised for many years can determine the best response to nitrosative stress induced by peroxynitrite.