Gym etiquette is based on standard courtesy. EOS Fitness vice president of operations and sales Eric McCauley says basic etiquette boils down to three rules: clean, rerack your weights, and let people work in.

“If you’re doing those three things, everybody’s happy,” he says.

Why cleaning is polite is hopefully self-explanatory. Just like eating at a dirty table with miscellaneous food bits is unpleasant, it’s uncomfortable to use equipment that’s wet with a random person’s perspiration. Gyms are communal spaces where people sweat, spit and sometimes smell, and it’s easy to pass germs. For this reason, gyms have paper towels and spray for people to spray equipment after use to keep it clean for the next person.

Reracking weights keeps spaces organized and saves others from picking up after you. Abandoning a squat rack fully stacked with 100-pound plates could render the station useless for younger people or elderly folks who may not be able to remove those heavy weights. You’re there to work out; why not burn a few extra calories by putting your weights back?

While etiquette hasn’t changed for decades, phones have changed gym goers’ behavior. People will film themselves or linger on equipment between sets, exercising only their scrolling finger. MaCauley says to let people work in, meaning share your station or machine while you are between sets. This way people don’t have to wait so long to use the limited equipment.

And be conscientious of what you film, he adds, since not everyone is comfortable being on camera. Gyms haven’t become content creation studios just yet.

“I know people want to take selfies. I know people want to talk about the gym experience, but not everybody wants to be on camera,” he says. “Be aware of your surroundings when you’re doing that.”