The effect of physical conditioning suggests adaptation in procoagulant and fibrinolytic potential.

Acute exercise evokes a transient increase in procoagulant activity. We evaluated the effect of physical conditioning on the activation of the coagulation and fibrinolytic systems. Two groups of subjects of different aerobic endurance levels (athletes and controls with maximal oxygen uptake (VO2max) 68.4 and 52.6 ml kg-1 min-1, respectively), were tested at rest and after standardized exercise at 80% of their individual VO2max. There was a significant increase in prothrombinfragment 1 + 2 (F1 + 2) level among controls in response to standardized exercise (p < 0.05), whereas no significant difference in the level of F1 + 2 between athletes and controls at rest or in response to exercise was demonstrated. Tissue plasminogen activator (tPA) antigen level at rest was significantly lower in athletes compared to controls (p < 0.03). A significant increase was found in the tPA level after standardized exercise in both groups (p < 0.02), which was lower in athletes compared to controls (p < 0.05). There were no significant differences between athletes and controls in plasminogen activator inhibitor-1 (PAI-1) and thrombin antithrombin complex (TAT) levels at rest. Athletes had a significantly lower PAI-1 level than controls after exercise (p < 0.05). In conclusion, the present study suggests an increased activation of the coagulation system in response to exercise in controls only. It also suggests adaptive changes in fibrinolytic potential induced by physical conditioning, as demonstrated by the lower level of tPA at rest and the lower levels of tPA and PAI-1 after exercise in athletes compared to controls.