Reading through this thread has been interesting for me - and has me straining to remember back almost forty years to my own high school gym experience.
I could have been interested in various gym programs, but I was absolutely terrified at the idea of showering with the rest of the class. I remember going into the locker rooms the first day, unlocking and locking back up the basket assigned to me, but I don’t recall ever going in there again. I never even bought a gym suit.
I didn’t have much of a problem with bullies. I was by far the tallest kid in my grade, and, while I was not particularly outgoing or aggressive, bullies did not find me a soft target. I was, however, a very private and introverted kid, and the idea of being naked in a group was very foreign.
The main gym teacher was old school, but my teacher was new, a young guy, and somehow (I really don’t remember how) we came to some sort of agreement. I never went to class, but he kept passing me through. I don’t know what he thought – perhaps he figured I was gay or something (I’m not), but, in any case, he was understanding. The old coach didn’t like it much, but it wasn’t his call.
We had to have four semesters of gym to graduate, and my teacher left after my third semester. I actually didn’t even know we had a new teacher, and wound up failing the fourth semester. Eventually, in my senior year, I went back to the new guy and arranged to get credit for outside exercise (I lived and worked on a farm, and got plenty!)
The 70s were a time when school programs underwent a lot of change. Class requirements were changed - dumbed down in a lot of cases. One year survey courses (like Biology) were split up into a variety of one-quarter specialty courses, from which the student could pick subjects which struck their interest. Homework was made optional. Perhaps a similar attitude was taking hold in the PE department.
So I kinda lucked my way through it. It might have been better if I had wound up with the old-school teacher and I was forced to break out of my shell – but it would not have been comfortable.