The paper presents an investigation into the changes in the hemostasis system of rats during extreme exercises. It has been observed that a single two-hour swimming exercise and an eight-hour imposed running in the treadbahn are accompanied by the expressed shifts in hypercoagulation with the signs of thrombinemia. On the background of the decrease in the anticoagulative and fibrinolytic activity it creates a serious threat of intravascular blood coagulation. The preliminary thirty-day course of extractum Eleutherococci eliminated the signs of intravascular blood coagulation.