Mine is around 55-60 in the morning, but throughout the day it's in the 70's. My HR does drop back to normal quickly after elevating above 140 or so, it's been like that as long as i can remember. The lowest i've seen mine was 48 and that was years ago after i lost a lot of weight and was doing intermittent fasting.
In college this guy had a resting heart rate in the low 30's, i remember the physician told him to eat more meat. The guy was about 155 pounds and 8-10% BF, could run 10 miles like it was nothing.