Just wondered: Is it normal that my legs always seem to be tired when I climb just a short flight of stairs. I do about 30KM's a week and still even on my off days the stairs at work just gets the better of me. It is not that I stay tired or anything, it is just that I would expect that being quite fit, my legs should not even wink after climbing 100 stairs! What can this be and is it only me!?