Thanks Brian. You confirmed what I was thinking. It’s nice to have another perspective. It can be difficult trying to sort these out on your own. I did a one hour run the other day at the higher heart rate and faster pace. It felt good, but definitely more intense than what I’ve been doing and not something I would want to do for 3 hours. I’ll keep trying to zero in on my AET and will incorporate one run a week at the top of my AET and then see if I can zero in on my LT. I’ve been running slow and easy for so long, I think I need a bit of time before I’ll be ready to run hard. Thank you again.