Effects of exercise on parameters of blood coagulation, platelet function and the prostaglandin system.

Acute exercise causes a temporary short lasting activation of blood coagulation, platelet function and the prostaglandin system, the extent of these alterations being significantly less pronounced in well trained athletes than in untrained persons. The reversal is also much faster in athletes, thus providing an underestimated indicator of the individual training status. Changes in platelet function and some plasma parameters of coagulation exhibit a significant correlation to base excess, pH and lactate. Immediately after acute exercise there is, therefore, an increased risk for acute thrombosis if an additional risk such as doping and/or smoking and/or contraceptive pill use is present. This risk is again higher in untrained than in well exercised persons. Patients with clinically manifest atherosclerosis (predominantly with risk factors) performing only occasionally anaerobic exercise are more likely to be at special risk. The overall response of the coagulation system, platelet function and prostaglandin system is significantly impaired. In contrast, regular exercise causes decreased activity of platelets and the coagulation system resulting in an improvement in haemostatic balance. As well as the psychological factors beneficially influencing the subjective feeling, it seems rather likely that the above mentioned mechanisms may be one factor underlying the decreased death rate from cardiovascular disease in persons performing regular physical activity.