Doesn't matter how fit I am, my resting heart rate is always way higher than others. There were guys on my college team who were slower, and guys that I raced against after college who were also slower, but all had way better sounding stats like resting hearts that were lower, better blood pressure that was lower and they were leaner like around 5-6% body fat.
Around the first time I ran a 65:xx HM, my heart rate was 56 at doctors. Fell asleep with heart rate monitor on one time on accident and it got down to a whopping 50. My bp is 130 over 80 and my Iron is always low like in the 15-20 range unless I dose regularly to get it beyond that. Additionally my body fat % is always closer to like 9-10%. Even at best racing shape
I also had similar numbers in college when I was a 14:30s/3:50 guy.