My heartbeat is usually between 40-50. Anything in the 60's is high. When I exercise it can get to 90, but I have asthma, so i can't really exercise easily above that. I'm not athletic. (Why the hell would I be on this kind of forum if I was?) I'm not the most fit. (Slender, but I can't run the mile in five minutes) My mom's heartbeat is slow, too. Is that why? Just curious for input.