Exercise-induced activation of blood coagulation and fibrinolysis

In the healthy individual physical exercise gives rise to an activation of blood coagulation. Exercise at the anaerobic threshold (about 90% of maximum heart rate) lasting 30 to 60 minutes leads to a minor formation of thrombin and fibrin as indicated by slight but significant increases of plasma levels of prothrombin fragment 1+2, thrombin-antithrombin III complexes and of fibrinopeptide A. This activation of coagulation with exercise is accompanied by a concomitant activation of the fibrinolytic system as reflected by increased plasma levels of fibrin degradation products and of plasmin-antiplasmin complexes. Moderate exercise over 1 hour (about 80% of maximum heart rate) - in contrast to heavy exercise at the anaerobic threshold - does not result in enhanced thrombin or fibrin formation while fibrinolysis is significantly activated. Also in patients with coronary artery disease exercise at moderate intensity as relevant for cardiac rehabilitation does not result in an abnormal formation of thrombin and fibrin with exercise. Conclusions: Activation of blood coagulation during strenuous physical exercise is accompanied by a simultaneous activation of fibrinolysis suggesting that the hemostatic balance is well maintained also during heavy physical activity. Moderate exercise that is recommended for the prevention of cardiovascular disease results merely in an activation of fibrinolysis.