Yes, 60 to 100 rest HR may be "normal" for adults, but I'd expect an athletic person to run closer to 60, I did up to the age of about 65. I quit running at age 67 when I when in to full time AFib and remain so now, two years later. I'm drugged enough now with Beta Blocker meds that my HR has no meaning other than it isn't too high.
I'm not sure about your concern about damaging your heart is you work out at near your maximum HR, of approximately 180. I have always exercised very near my maximum HR, and when 65 that was 155, which was the point at which I would start to consider slowing down. As I always wore a heart monitor I would then try to hold at about 150 for 30 minutes or so. Then too , I have AFib, so how much you want to take from my model could be none. I do not believe my AFib and my exercise regiment are related. I had a leaky Mitral valve that caused my left atrium to enlarge to a point that it caused AFib. The valve has been repaird, back when I stopped running at age 67. Still not running as I can't shake the AFib.
To be honest, I don't know. I really only started using the HR monitor on a very limited basis early last year and didn't start using it regularly until a few months ago. And before that I never had a concern over the actual heart rate....from the issues I had with running I automatically assumed in the beginning that it was a lung related issue (asthma - reg or exercise induced, etc.) and pursued treatment on that basis. After seeing my heart rate and finding that all other tests came back negative, I have to assume it is the heart. From all the reading I'm doing on the topic, the normal adult heart rate (very generally) should be between 60 and 100 bpm with 75 being considered the average for a normal healthy adult.
As far as the heart rate during exercise, from everything I've read I'm about 20 to 30 bpm higher than I should be for endurance exercise. My heart is beating between over 170 bpm for 20 to 30 minutes. From what I understand this can damage my heart if done on a regular basis. Over a period of 4 months, shouldn't there be some decline in my heart rate when running at the same pace?
The running HR doesn't strike me as too high for someone who is working up to running again. The 72 at rest seems a bit high, however. Has you rest HR always bee high? Given you physical activity history I'd expect a HR in the low 60s to be expected. I say this knowing that some people have a higher HR, suppose it has something to do with the size (volume) of their heart relative to the size of their muscles/body.