Acute physical exercise is safe in patients with primary antiphospholipid syndrome with exclusive venous thrombosis and under oral anticoagulation with warfarin.

The purpose of present study was to evaluate the effects of maximal acute physical exercise on prothrombin time/international normalized ratio (PT/INR) in patients with primary antiphospholipid syndrome (PAPS) under oral anticoagulation with warfarin and the safety of acute exercise in regard to thrombosis and bleeding risk. Eighteen physically inactive women with PAPS (Sydney criteria) with exclusive venous events and without thrombocytopenia were included. All patients were under stable warfarin therapy (PT/INR target: 2.