I have a lot of thoughts about this.
I saw a comment on here not long ago about PE teachers which made something kind of click into place for me. In my experience a lot of PE teachers will engage with the kids they think are "good at PE" and not with the kids they think are "bad at PE". There seems to be little if any acknowledgement that PE is a school subject just like any other, where teachers should be required to actually teach children and help them to improve their skills. I think the person who made that comment referred specifically to being required to run cross country and hating every minute of it, and nobody ever explaining to them that running is a skill just like any other, and if you do it regularly it will get easier and you will get better at it.
I hated PE in general because I thought I wasn't a sporty kid, because it was something the cool kids were good at and I wasn't cool, or maybe the other way around, that kids who were good at PE were cool so I could never be cool because I wasn't good at PE.
It also didn't help that my parents didn't give a shit about PE. It was the one subject that they couldn't care less about on my school report. They weren't sporty themselves, never have been, and didn't see the value in it. I sometimes wonder, if I had been sporty and had won races or matches, whether they would have been as enthusiastically supportive as they were of my other interests and academic achievements, or whether they would have just nodded in a slightly bemused fashion and said, "That's nice, dear."
I also hated being made to run around in the cold during winter wearing flimsy PE kit, hated having to get changed in the classroom in primary school, and hated being made to shower in front of the other girls after PE in secondary school when I was self-conscious about my developing body. A body I might have been less self conscious about if I had spent more time doing sport and been as fit as a fiddle.
It literally never occurred to me until I was well into adult life that I could choose to do sport, as a means to fitness or even for enjoyment, and that if I put regular effort in, I could even be good at it.