My RHR was in the hundreds when I had an overactive thyorid and it's been in the thirties for the last decade or so because it's underactive, so I place no truck with its readings, it just seems to be under external control rather than any fitness level. My fitness has varied a lot in that time, up and down depending on how busy I am with work, and it's not made an ounce of difference. Interesting that you guys can relate yours to cardio levels.
My GP has zero interest in my low heart rate. They were concerned about the fast heart rate alright.
I've bought way too many sweets and chocolates for the amount of trick or treaters I've had so far this evening. Need to step away from the sweet bowl!