Inclusion Criteria:  Participant (if 18 years of age or older) or parent/LAR is willing and able to provide written informed consent; minor participant is willing and able to provide assent, if applicable based on site and local regulations Male participants with moderate to severe Hemophilia A ( FVIII activity </= 5%) between 6 to <19 years of age without inhibitors are eligible for participation in this study Participants must be on Emicizumab or standard FVIII prophylaxis per institutional/primary hematologist recommendations Participants must be engaging in sports activities with moderate to high risk of bleeding as defined by the NHF- Play it safe guidelines Participants must be compliant with completing all bleed and treatment logs Participant must be compliant with use of wearable activity tracker  Exclusion Criteria:  Participant/parent/LAR unwilling to provide informed consent/assent Unwilling to log or document bleeds and treatment information as per study guidelines Participants with any other bleeding disorders will be excluded Participants on concomittent FVIII replacement and emicizumab for sports participation