jotis,
If your question is referring about playing sports as an Admissions requirement, consider that about 88-90% of each class participates in varsity athletics. If you are one of those ~10%, I would HIGHLY suggest finding another way to demonstrate that you are physically fit -- i.e. JV sports, participate at local sports club, run monthly road races, participating in league sports, etc. Additionally, your Candidate Fitness Assessment will also be looked at more closely.
If you are referring to while at USNA, there are two good posts above.