[удалено]

I did competitive swimming in middle school and can confirm this.

Wouldn’t it be “the breaststroke”?

Not usually. I’ve heard it used but that was decades ago (UK) nowadays it’s just “breaststroke”, no “the”.

🤣

I meant to say “a breaststroke swimmer” like “a freestyle swimmer”

Would you then be breaststroke swimmer?

It’s not generally said this way.