According to the American Heart Association, the broad,
approximate guideline for your MAXIMUM heart rate is:
-- take 220
-- subtract your age
The unit is "beats per minute".
But there are many things that have an effect on this number.
A few of them are:
-- your age
-- your weight
-- any medicines you're taking
-- HOW you measure your heart rate.
If you're planning any REGULAR activity that will play with
your heart rate, you really ought to discuss it with your doctor
before you jump in.