Physical exercise and hemostasis.

A number of hemostatic changes involving platelets, coagulation and fibrinolysis have been reported after acute physical exercise. Results have sometimes been controversial, due to differences in subjects investigated, type of exercise and methods used for hemostatic evaluation. On the whole, physical exercise has been shown to induce: (1) increases in platelet number and activity, (2) activation of coagulation leading to a slight but significant thrombin generation and (3) activation of fibrinolysis. These changes are short lasting. Less known are hemostatic changes induced by exercise training programs: a few data are available on the effects on platelets and coagulation, whereas studies performed on fibrinolysis show a decrease in plasminogen activator inhibitor-1 levels at rest and an increase in fibrinolytic capacity after training.