I just got a HR monitor and will be using it to train over the winter (and beyond). It had me put in height, weight and age and calculates three pre-set zones. I know that it's using 220-age in its calculations of the maximum HR. There is a fourth user profile that I can custom set.
Here is my question: If I have a resting HR of 55 and another person has a resting HR of say 70, shouldn't our numbers and zone percentages be different?
I'm 58 yo so 85% of my max is 138 (220-58=162*.85=137.7). That means that at 85% of my max I'm working at approximately 251% (138/55=250.9) of my resting rate. The other person of the same age with a 70 resting HR would have the same 85% of 138 but is working at 197%.
I know that 220-age is a generalized formula but is there another formula that more accurately uses resting heart rate as a basis, or am I overthinking my new toy?