I don't know what my absolute max HR is, but the highest it's been in the last few months was 179 towards the end of a 10mTT. I often see that other peoples HR seems to be higher and sometimes wonder if it's because I'm soft, but yesterdays 50 definitely felt like tough work to me... 166 average for the full 50, 172 Max. Generally I just put it down to individual variation.
I think you were correct when you said that a high max HR is a result of having a small heart which would need to beat faster to get the same flow rate.
I don't know what my absolute max HR is, but the highest it's been in the last few months was 179 towards the end of a 10mTT. I often see that other peoples HR seems to be higher and sometimes wonder if it's because I'm soft, but yesterdays 50 definitely felt like tough work to me... 166 average for the full 50, 172 Max. Generally I just put it down to individual variation.