Lori, I'm 77 and my room is on the 2nd floor and I do those steps so much I try not to think about it..
BUT.......I look at it this way. The one old and the one new knees need the exercise.......lololol ........ as does the rest of the body.
I get too stiff if I sit in place too long, so the stairs are my jogging track.
When I PP, I get up from the machine and go to the ironiing board and back to the cutting table........
they are not far but those few steps each time, help to keep the joints oiled.