I never use elevators. Unless you are using a wheelchair (or, its an actual bone-fide skyscraper and we are talking 30th floor or above) I don't see why you would. More effort than they are worth (not to mention the one where I am now gets stuck rather frequently). Once lived on a 9th floor and never used the thing even then.
Some Swiss study found that those living above the 10th floor in high-rises had measurably better cardio-vascular health than those on lower floors. Though they don't know if that's due to walking up and down stairs or due to being above the pollution ceiling (and I also wonder if it's a selection-effect - those in poor health maybe don't want to live up there?). Though another study found those on higher floors were much less likely to survive if they _did_ have a heart-attack. Due to the delay in paramedics getting to them.