In adolescent male patients with mild hemophilia A, a new study examining changes in factor VIII activity (FVIII:C) with exercise, compared with intranasal desmopressin, showed both interventions to lead to increases in FVIII:C. However, the improvement was more sustained with desmopressin. The study results were reported in the journal Blood.

Persons with hemophilia (PWH) in the past had been advised not to participate in sports. “As the benefits of exercise and sports become apparent for PWH, treating physicians are faced with the dilemma of safely allowing sports participation while mitigating the potentially increased bleeding risk,” the study investigators wrote in their report. In this study, they evaluated the use of intranasal desmopressin in adolescent males with mild hemophilia A, which has been proposed for use prior to exercise.

The study ( Identifiers: NCT03379974, NCT03136003) was conducted both at the Hospital for Sick Children in Ontario, Canada, and at hospitals in Ohio. Male patients were recruited who were of ages 13 to 21 years and who had mild hemophilia A, with FVIII:C of 6% to 50%.

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Patients were randomized 1:1:1:1 to any of 4 study arms. In arm A, participants were assigned to receive intranasal desmopressin prior to an exercise protocol using a stationary cycle. In arm B, participants were assigned to intranasal desmopressin alone. In arm C, participants exercised and then received intranasal desmopressin. Finally, in arm D, participants were assigned to exercise only. Blood samples were obtained for analyses at baseline and at 3 time points over the study period, with the last sample obtained at 135+10 minutes after baseline.

The study included 32 participants, and the mean age was 16.1 years. At baseline, the mean FVIII:C value was 27.9%+18.4%. With exercise, participants experienced a 1.7-fold immediate mean increase in FVIII:C over baseline. After receiving desmopressin, participants had an immediate mean increase in FVIII:C of 1.9-fold over baseline (P =.04). These results suggested exercise was noninferior in terms of increasing FVIII:C over baseline.

However, hemostatic improvements experienced by participants after exercise did not last as long as they did with intranasal desmopressin; participants receiving intranasal desmopressin reached their highest median FVIII:C later in the study, with a plateau in the last time period of the study. Participants assigned to exercise reached their highest median FVIII:C earlier in the study, and it also began to decline earlier than with desmopressin.

Most (≥60%) participants who were assigned to both exercise and desmopressin, in either order, showed an FVIII:C of >50% at 75 minutes and 135 minutes after baseline. However, this was with significant variation between participants.

The investigators considered the study’s results to confirm earlier findings that aerobic exercise of moderate intensity is linked to an almost 2-fold rapid increase in FVIII:C in adolescent males with mild hemophilia A. They also determined that the FVIII:C increase was similar for exercise and intranasal desmopressin but was maintained for a longer time with desmopressin.

“Our work adds to a growing body of literature documenting the hemostatic advantages of exercise in patients with bleeding disorders,” the study investigators wrote in their report.


Kumar R, Dunn AL, Schneiderman JE, et al. Moderate-intensity aerobic exercise vs desmopressin in adolescent males with mild hemophilia A: a randomized trial. Blood. 2022;140(10):1156-1166. doi:10.1182/blood.2022016146