Changes in coagulation parameters with exercise in patients with classic hemophilia.

Vigorous exercise is known to increase VIII:C and VIIIR:Ag levels transiently in normal individuals. Although exercise programs are frequently advocated in the management of hemophilia, the effects of exercise on coagulation parameters in these patients have not been well studied. Eleven hemophiliacs were exercised on a bicycle ergometer to maximum voluntary effort as evidenced by an increase in pulse, blood pressure, and plasma catecholamine (norepinephrine and epinephrine) levels. The effects of this exercise on coagulation parameters, including functional and antigenic components of the factor VIII molecule, were determined. The entire group demonstrated a decrease in mean prothrombin time (11.7 to 11.2 sec). Four mild hemophiliacs demonstrated an increase in mean VIII:C (14.5% to 17.3%), and VIII:CAg (12% to 17.8%). Changes in VIII:C and VIII:CAg were not noted in the seven severe hemophiliacs. Both severe and mild patients demonstrated significant changes in fibrinogen, factor II, and factor VII after exercise. This study indicates that submaximal exercise modifies coagulation parameters in patients with hemophilia.