Hi. I climb the stairs to my new office, five flights. I’m always out of breath, but I go up and down 2-4 times a day. How often would I have to do it and for how long, such that my body could stand this without a noticeable raise on my part? I mean, shouldn’t my body adapt to this mildish exertion? I exercise twice a week.
Offhand, I’d guess that in order to go up five flights without getting out of breath, you’d have to practice going up ten flights.
Sort of like “how to catch tiger”–you catch ten, and let nine go.
I don’t think you’ll see optimal improvement if all you’re doing is sporadically climbing stairs. If you want to improve your aerobic conditioning (i.e. have better endurance and not get so out of breath) you need to raise your heart rate into the training zone and keep it there for at least 20 minutes, at least three times a week. (You should also warm up for at least 5 minutes first, and cool down for 5 minutes after.)
You don’t have to climb stairs to reach the training zone. A brisk walking pace on level ground should do it. But you do have to sustain your elevated heart rate for 20 minutes.
Climbing five flights of stairs is a significant amount of exertion. You shouldn’t expect that after a couple of months of aerobic exercise, you’ll be climbing them without getting out of breath. I do 30 minutes of high-intensity aerobic exercise 4-5 times a week, and I can’t climb 5 flights of stairs without getting a little winded. I am quite comfortable climbing 2 flights at a rapid pace, but above that I definitely start feeling it, and by 4 I’m breathing hard. Not out of breath, but sucking air. Then again, I don’t climb 5 flights of stairs several times a day. 
That will almost certainly work in your favor.
Also, you’ll have a nice motivation-feeback thing going on. You should notice some improvements after a few weeks to a month of consistent exercise. As your condition improves, you’ll be able to see how much further you can go without getting winded.
The usual disclaimers: YMMV, IANAD, etc. If you’re planning a significant change to your exercise plan, you might want to talk to your doctor.
From Podkayne’s remark, “I can’t climb 5 flights of stairs without getting a little winded” regardless of her training, it’s apparent the muscular development and endurance of your legs specifically is important. I’m sure she’s in far better shape overall than me, but I do two sets of 9 flights in my 15-floor apartment building and get slightly winded.
I suggest just increasing the number of flights you walk one time a day, and just do 5 the other times. I assume by your question your office is on the top floor, so at the top just walk down some extra distance and back up.
If you want to get in better shape generally, you need to exercise more than twice a week in addition to your stair climbing. Podkayne’s advice is good. I’ll add that you should add extra exercise gradually and on a schedule you can live with.
500 times
Thanks folks. I guess from the middle two writers that I can do some up and down in my condo building stairwell (4 flights) on non exercise days and see some improvement with that, too.