Busting it out at the Gym!

[Creekimp13 5,840]

Mine doesn't fall into the 40's ever.

Mid to high 50's at rest, even while sleeping.

I would mention the low heartrate to your doc, particularly if you have symptoms like fainting, dizziness or shortness of breath.

It could simply be excellent cardiovascular function brought about by diet and exercise. It's not unusual for athletes to have resting heart rates around 40.