Changes in blood coagulation and fibrinolysis associated with maximal exercise and physical conditioning in women taking low dose oral contraceptives.

Blood coagulation parameters (thromboplastin time. PT; activated partial thromboplastin time, aPTT; fibrinogen; antithrombin III, ATIII; von Willebrand factor-concentration, vWF; factor VIII-activity, FVIII) and fibrinolytic parameters (plasminogen; (alpha-antiplasmin; euglobulin-lysis-time, Elt; tissue plasminogenactivator-antigen, tPA-antigen; plasminogenactivator-1-antigen, PAI-1-antigen) were evaluated in 34 women on low-dose oral contraceptives (OC) twice at intervals of 12 weeks each time before and after maximal exercise. During the 12 weeks, 24 women took part in an aerobic conditioning program and 10 women were requested to avoid any kind of sports activity for this period. Blood samples were taken before training and before and after maximal treadmill exercise. This procedure was repeated after the training program. After maximal exercise we found a significant reduction of aPTT and PT (increase in %), a decrease in ATIII, vWF, fibrinogen, plasminogen and alpha2-antiplasmin but an increase in fibrinolytic activity (all p<0.05). Maximal exercise is associated with an increase in blood coagulation and fibrinolysis also in women taking OC. After the physical conditioning program an increase in fibrinolytic activity at rest was noted in the training group. Opposed to that the fibrinolytic activity at rest decreased in the control group after abstinence of sports activity over this period (p<0.05, MANOVA).