Going to the gym comes with its own set of rules and expectations. You can’t just go in there and do whatever you want. You’re entering an extremely delicate social contract. You have to be sure not to disturb the natural order of things, or else you risk getting kicked out. These rules and expectations might be outlined by the gym itself, and they’ll probably inform you of them when you sign up to become a member. These are the rules, like no listening to music out loud or no slamming overly-heavy weights on the ground. 

But then there are the rules that you have to intuit just by being a regular, considerate person. These are the more subtle social cues, like letting someone rep in on your weights and not hogging a machine for hours. These you pick up just by following common sense and exhibiting some empathy. This woman managed to cross all of those boundaries in one fell swoop, and her fellow gym-goers had a lot to say about it, and a lot of it wasn’t kind to her.