Activation and disturbance of blood haemostasis following strenuous physical exercise

Physical exercise activates blood coagulation and enhances fibrinolytic act ivity. To investigate whether these activations of blood coagulation and fi brinolysis are balanced post-exercise and during the period of recovery, 11 moderately active young men were examined immediately after a standardised cycle ergometer test and during the 24 h period of recovery. Blood samples were obtained at rest, immediately after exercise, and 2, 6 and 24 h after exercise. All post-exercise values were corrected for any change in plasma volume. Exercise induced a significant increase in factor VIII activity an d this occurred with a significant shortening of activated partial thrombop lastin time. A concomitant enhancement of tissue plasminogen activity resul ted in significant increases in tissue plasminogen activity antigen and tot al fibrin/fibrinogen degradation products, and a significant decrease in ti ssue plasminogen activator inhibitor-1 activity. Increases in coagulation a nd fibrinolytic activity changed in parallel during exercise. However, duri ng recovery, while the increase in factor VIII activity post-exercise persi sted 2 and 6 h into recovery, fibrinolytic activity demonstrated a sharp fa ll. It is concluded that whereas the enhanced fibrinolytic activity during exercise appears to counterbalance the increase in blood coagulability, thi s haemostatic balance is not maintained during recovery. This perturbed blo od haemostasis could constitute an enhanced risk for coronary artery thromb osis and may contribute to exercise-related cardiovascular events.