Nothing against senior citizens, but they tend to have more time on their hands and their schedules aren't as tight as people who've got to work. You might be curious about the tumors they want to tell you about, but you're probably in a hurry, too. You're there to work out, but you also want to be tactful.
Perfume isn't really necessary when you're working out. Or cologne. Some people really splash it on and that's not good if you're allergic to it.
Gyms deal in sweat. It's OK to be stinky. But in a confined space, like a spinning room, it can be unbearable. You do need to monitor yourself.