At junior school we went to swimming once a week at a local pool, and the resident coach terrified us. He did not succeed in teaching any of us to swim; he threatened us with a long wooden pole when we were in the water, then when we were getting changed in curtained cubicles that surrounded the pool, he would pull open the curtains and shout at us to hurry up.
Of course, we knew nothing of paedophiles back then, so we just guarded one another, by one girl getting changed while the other gripped the curtain to keep it closed!
Later, at grammar school our PE mistress was abusive in a different way. She was just plain nasty to non-sporty types like me. Outside of school I did sports that were nothing to do with school - judo and cycling - and loved the way the coaches and experts were kind to us. Huge contrast. At judo we were taught 'breakfalls' which involved a sort of forward somersault and landing in a certain way. At school in gym one day we had to do something similar, so I did it really well. She was beside herself with fury at not being able to make her usual nasty criticism, but she could not say anything.
My one little triumph.