Oxidative stress and hemorheological changes induced by acute treadmill exercise.

The present investigation was designed to evaluate the acute effect of aerobic exercise on oxidative stress and the flow properties of the blood. Fourteen clinically healthy subjects (7 men and 7 women aged 56+/-19 yr) underwent maximal treadmill exercise with blood samples drawn prior to and immediately after exercise. Post-exercise significant increases were observed in plasma lipid hydroperoxides from 6.5+/-2.0 microM to 7.9+/-1.9 microM (p<0.0001) and the relative concentration of plasma fluorescent products associated with red cell peroxidation from 138+/-28 RF to 220+/-92 RF (p<0.005). After exercise there was a rise in the hematocrit from 41.4+/-3.7% to 44.4+/-4.1% (p<0.0001), increases in whole blood viscosity at shear rates of 22.5/sec to 450/sec (p<0.0005), an increase in plasma viscosity from 1.27+/-0.12 cP to 1.36+/-0.11 cP (p<0.01), an increase in red cell rigidity from 2.44+/-0.48 cP to 2.62+/-0.42 cP (p<0.001) and a decrease in erythrocyte sedimentation rate from 26.9+/-18.6 mm/h to 22.5+/-15.9 mm/h (p<0.01). The findings suggest that acute aerobic exercise induces oxidative damage to red blood cells and adversely affects rheological properties of the peripheral blood.