A new study from Japan is shedding light on how often boys and young men with hemophilia can safely participate in sports, and why early adolescence may be a particularly important time to monitor bleeding risk.
The research suggests that playing sports three or more times per week may increase the likelihood of sports‑related bleeding episodes in youth with hemophilia, even for those on prophylaxis.
What the Study Found
Researchers reviewed the medical records of 23 boys and young men with hemophilia, ages 14 to 23. Most had hemophilia A, and nearly all were receiving prophylaxis. The majority were active in sports, with baseball, swimming, and soccer being the most common activities.
Key findings include:
- 57 sports‑related bleeding episodes were recorded among 15 participants.
- Bleeds occurred in joints, muscles, and under the skin.
- 84% of bleeds happened during higher‑intensity or contact sports such as baseball, soccer, and basketball.
- Bleeding episodes were most common during junior high school years (ages 13–15) — a period marked by rapid growth and increased physical activity.
- Youth who played sports three or more times per week had more than double the odds of experiencing a bleed compared to those who played less often.
- Interestingly, hemophilia severity was not strongly linked to bleeding risk in this study; frequency of activity mattered more.
Modern prophylaxis has made it possible for many people with hemophilia to safely enjoy sports and physical activity. Still, this study reinforces what many clinicians already recommend: activity‑based treatment planning matters.
