My thoughts are in this thread:
What you need to remember is that you’re not training by pace anymore.
Your RPE 6 pace will be affected by your rest, fatigue, weather, elevation change, and so on. Unless you always feel great, run on flat routes in windless perfect temperatures of course.
That said, and as per my link, I used paces to gauge effort when I am on the flat and feeling good. Then take that effort and keep it as the elevation/weather/illness strikes.
For VO2max efforts, I know how my breathing and effort feels at VO2max, so i don’t need a pace at all.
