That’s exactly what I was thinking. I did my long run yesterday, 20km and average 11:00 minute miles and 70% of max HR rate. That would put me comfortably in Z2 and I would say it was my run all day pace. If I had to attribute an RPE valuable to the run I would say 4 possibly 5. This is the pace I have been told I should be running an ironman effort because of the nature of the race.
RPE 6 would put me in my ‘grey zone’ or zone 3 I think?