Hemophilia A (HA) is a genetic bleeding disorder resulting from a deficiency or absence of factor VIII (FVIII), which is necessary in the clotting process. This disorder occurs mostly in males and in severe cases causes frequent bleeding episodes in joints and muscles which can lead to progressive damage that affects mobility and quality of life. Prophylactic FVIII administered intravenously every other day has been the standard of care treatment for HA for the past few decades. Sports and physical activity are generally encouraged in patients with hemophilia on appropriate prophylactic treatment to increase strength, prevent or decrease obesity, accrue and maintain bone density and encourage normal socialization. To ensure safety with participation in sports in persons with hemophilia A (PWHA), timing of FVIII administration is often adjusted to maximize FVIII at the time of sports. The exact factor level that is needed to safely participate in sports and minimize bleeding risk is not yet known. Based on clinical practice, infusion of FVIII to near the lower limit of normal right before participation in sports generally works to prevent bleeding. The study is looking at how well the newly approved medication Emicizumab works compared to Factor VIII to prevent bleeding in patients with Hemophilia A who play sports. The study will enroll children and adolescents who are already on Emicizumab or Factor VIII who are currently playing sports.