Miss Manners: Should I ask people at the gym if they’re done or just resting between sets?

Dear Miss Manners: When people sit on machines at the gym that others want to use, texting and reading their phones, they may just be taking a break between sets. Usually there are three sets of 10 to 12 reps, and they rest their muscles for a few minutes in between. Sometimes people are willing to alternate with someone else during their rest period.