Blood coagulation and fibrinolysis at rest and in response to maximal exercise before and after a physical conditioning programme

Twenty-five young subjects were divided into experimental (n = 13) and control (n = 12) groups in order to examine the acute and chronic effects of exercise on blood coagulation and fibrinolysis. Blood coagulation and fibrinolysis variables were ascertained in both groups before and after a physical conditioning programme both at rest and following maximal exercise. The experimental group exercised for 12 weeks [30 min, 3 x week at 70% (6 weeks) and 80% (6 weeks) of maximum heart rate]. The control group maintained normal activity patterns. Significant activation (P < 0.05) of blood coagulation was observed in response to maximal exercise before and after the conditioning programme in both groups in activated partial thromboplastin time (AMT), thrombin clotting time (TCT), factor VIII procoagulant activity (FVIII PA) and factor VIII antigen (FVIII A). Likewise, blood plasminogen activator showed a significant increase (P < 0.05) in response to maximal exercise before and after conditioning in both groups. Although VO2 max following the conditioning programme was significantly increased in the exercise group versus control, no significant changes (P > 0.05) were observed in either group in blood coagulation and fibrinolysis parameters at rest or in response to maximal exercise. It is concluded that maximal exercise transiently accelerates blood coagulation and activates blood fibrinolytic activity, however physical conditioning appears not to influence the haemostatic and fibrinolytic systems at rest or in response to maximal exercise.