My general approach to Aurora rides is valleys in the 50s and plateaus in the mid 60s — sprinting every 2 minutes — but the posted pattern of someone on FITIV got me to thinking about plateaus in the mid 70s and valleys in the mid 40s. My FITIV pattern does not reflect this difference but I can feel it while riding.
My usual heart rate in sprints is in the 170s so you can see the effects of those 140’s valleys.
Ecbatan 