I just wanted to add a quick note on barbitu8’s formula using 220-age. I work in a cardiology office and that is also the number we use to estmate MHR. I also agree with what others have said here that a MHR calculated using only age is not going to be very accurate.
OK, so what’s a resting heart rate? When do I measure it?
If I’m lying in bed, my heart rate’s in the mid-fifties. If I’m sitting at my desk at work, it’s in the mid-sixties.
Your HR after awakening is the slowest. Wait a minute after awakening and take your pulse.