Dose-response and coagulation and hemostatic factors

Abstract
The purpose of this study was to evaluate the dose-response relations of regular physical activity on platelet function, blood coagulation factors, and fibrinolytic factors, on the basis of studies with appropriate experimental design. MEDLINE-based literature search supplemented with relevant review articles and other individual articles was used. The review concentrates on controlled randomized clinical trials on the impact of regular physical exercise on platelet function, and on blood coagulation and fibrinolytic factors. Physical exercise acutely activates platelets and the fibrinolytic system, and some factors of the blood coagulation cascade. These findings, the earliest of which were published already in the 1960s, are mainly derived from uncontrolled observations. These studies have led to the conclusion that unbalanced activation of the hemostatic system during acute exercise may be part of the mechanisms for sudden cardiac events during or shortly after heavy physical exercise. The effects of regular physical exercise on various aspects of platelet function, blood coagulation, and fibrinolysis have been the object in only a few controlled randomized trials. With the exception of data on platelet function, the results remain contradictory. Controlled randomized clinical trials with adequate statistical power and experimental study designs with subjects of different ages and health status are warranted for the evaluation of the dose-response issues to clearly delineate the preventive and therapeutic potential of regular physical exercise.