When sitting at the computer my pulse rate is normally about 55.
Last week, I tore a heart rate monitor on a 75 mile ride. Unfortunately it was a cheap one which didn't record the extremes, but the highest I saw it get to was 140 bmp. As it happens at that point I had just been joined by my fit, 30-year-old nephew (a chance meeting) who is a doctor. His words were "120 to 140 is a good place to be when cycling." This was after about 63 miles and he had caught me up on a long climb.
I was very encouraged to watch the rate rise and fall directly in proportion to the road. However, I have noticed that after a day's riding, once I get back home my hr will stay aroundd the 70 mark for quite a long time before returning to somewhere between 50 and 60.
I'm 110kg (>17 stone) and 5' 10".