[mikestew]

Serious distance runner here: about five years ago while laid up in the hospital the alarm kept going off in the middle of the night on the HR monitor machine.

Nurse: “it goes off if your HR is too low.”

Me: “what’s it set to?”

Nurse: “39 BPM”

Me: “ yeah, you’re going to want to turn that down a few notches.”

Genetics play a role, too. Back in the day, one of the fastest road bike racers in WA state told me he’d never seen his resting HR below 60.