It doesn't matter whether your MHR is high or low. It's just a measure of your MHR. Some people have big hearts that beat slowly and some have small hearts that beat quickly.
If your RHR is 36 it suggets to me that you have a very big heart that beats slowly.
Use 165 as your max for now. Monitor it and wear your HRM in a 10k race. See what it says then.
Interesting result on Sunday. Hilly trail. Comparing last years race with Sunday's.
Last year 1:59:24, yesterday 1:55:05.
Last year Avg HR 172, Sunday 165.
So I think maybe I wasn't pushing hard enough yesterday, maybe I've forgotten how hard I can push?
Still 4mins off last years time in much hotter conditions. So I'm reasonably happy.
Next two races are St Albans and The Surrey Badger. Neither of which I will run as 'Races' as I'm going to accompany some novices. Think I'll see if there's something else local soon.
I found the long slow runs have really bought my base heart rate down. Previously a 9:00/mile would have me struggling at 170. Now I can't get over 160 without some serious sustained effort at 7:30/mile.
Sunday I ran 17miles at 9:30 and my heart rate averaged 150.
I've a feeling I'm just not pushing hard enough in a race.