Ah, high school gym classes. I remember thee well.
There's a reason baseball is the american past time. From my memories, its long, painful, and almost always unfair.
In anycase you could do what I did: wait it out and then never take a PE class again and become a theatre major.
You're an incredibly mature, intelligent girl Fidds. I don't doubt that there is a teacher that you are friendly with that respects you. If that teacher can broach the subject, it might be a good method.
Bear in mind that there are some teachers that can't work with people. In these cases the best you can do is stomach it and warn younger students to avoid classes at all costs. Its an unfortunate situation, but sometimes its all that can be done. There's certain English prof many of my fellow students affectionately refer to as "Satan," that has put many of us in a similar position.
Or there's always a good old fashioned class revolution which could be in order...
Not that I've had any experience with that...
Power to the students!
Good luck! If anyone can pull it off you can!