That's is a f'n low resting HR. Mine runs 50-52 or so most days. Well doneOnly a tiny bit, that is only just into overweight. But you are right, BMI does not work for many body shapes, I'm 6' 6" again lately (lost a bit with scoliosis but straighter now) and at 290 I'm a lot of muscle and very little fat, around 12%. BMI has me at obese.
My resting heart rate is now 42.
That said, Americans are the heaving trough hogs of the world and it is hard to have sympathy for this self-abuse.
