The acute effect of moderate intensity aquatic exercise on coagulation factors in haemophiliacs.

The objective of this cross-sectional study was to analyse the acute effect of aquatic exercise on haemostasis in persons with haemophilia. Ten adult haemophiliacs (8 type A, 2 type B) familiarized with aquatic training performed a 20-min exercise session in a swimming pool at an intensity of ~70% maximum heart rate (HR). Blood samples were collected immediately after the training session. The haemostatic parameters selected for analyses were factor VIII (FVIII), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen. There were unclear effects of the exercise bout on FVIII and APTT, with a possibly beneficial effect on PT (-11·4%; 90% confidence interval: -26·1;3·3%), and a trivial change on fibrinogen levels. It was found an association between the mean rise in HR during exercise and the decrement in PT after exercise (r = 0·729; P = 0·026). The greater changes were observed in the patients diagnosed with a moderate level of haemophilia. It is concluded that a short bout of moderate intensity of aquatic exercise may have a positive influence on PT in adults with haemophilia with greater changes in those individuals exhibiting a greater rise in HR during exercise. This may be an important issue to the haemostatic control of haemophiliacs in clinical settings. Further studies are warranted for testing the influence of different aquatic exercise intensities on haemostasis.