Background: The oxidative stress results from a change in the physiological balance
between oxidant and antioxidant species. The purpose of this study is twofold: first, to investigate
the effects of long-term training in sports with high energy requirements on the redox balance
which exists between the plasma vs. the erythrocytes; second, to study the activity of the PMRS
(Plasma Membrane Redox System), which is a compensatory mechanism of cellular redox
homeostasis, in the rowers’ erythrocytes in order to determine the rowers’ counteraction to
oxidative stress.
Methods: Venous blood samples was collected from rowers and control group; then FRAP
(Ferric Reducing Activity Power) method has been used to determine the antioxidant capabilities
both in the plasma and in the erythrocytes of 22 rowers vs. 26 sedentary subjects. For the same
groups of subjects, the PMRS in erythrocytes has been also evaluated.
Results: The plasmatic antioxidant activity was 21% lower in the group of rowers compared
to the sedentary group (p = 0,02). In contrast, no significant differences were found in the reducing
activity of the erythrocytes; however the erythrocytes of the rowers have shown values of the
PMRS 35% higher than the untrained group (p < 0.0001).
Conclusions: Rowing induces a significant oxidative stress in the plasma corresponding to
the high intensity training, while this effect lacks in erythrocytes. At the same time an increased
quantity of the PMRS has been observed in the erythrocytes. In conclusion, in well trained athletes
this not lead to established an oxidative stress condition because long-term training adaptatively
improves the efficiency of the antioxidant syste
