Activation and Disturbance of Blood Haemostasis Following Strenuous Physical Exercise

Physical exercise activates blood coagulation and enhances fibrinolytic activity. To investigate whether these actiivations of blood coagulation and fibrinolysis 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 exerciise, 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 and this occurred! with a significant shortening of activated partial thromboplastiin time. A concomitant enhancement of tissue plasminogen activity resulted in significant increases in tissue plasminogen activity antigen and total fibrin/fibrinogen degradation products, and a sigmificant decrease in tissue plasminogen activator inhiibitor-1 activity. Increases in coagulation and fibrinolytic activity changed in parallel during exercise. However, during recovery, while the increase in factor VIII activity post-exercise persisted 2 and 6h into recovery, fibrinolytic activity demonstirated a sharp fall. It is concluded that whereas the enhanced fibrinolytic activity during exercise appears to counterbalance the increase in blood coagulability, this haemostatic balance is not maintained during recovery. This perturbed blood haemostasis could constitute an enhanced risk for coronary artery thirombo-sis and may contribute to exercise-related cardiowascular events.

Key words

Exercise - blood coagulation - fibrinolysis - Ihaemo-static balance - thrombosis