Zone 2 Rides (Power vs. HR)

I know that for SS4 some Z2 rides are prescribed by HR, which is often how I do my Z2 rides anyways, but quick question based on one of my favorite rides. Climbing is one of my favorite things about riding a bike and living here in Colorado. One of my favorite endurance rides is a roughly 43 mile route with ~4,000 ft. of climbing.

I did that ride Sunday of this past weekend averaged 143 BPM and 146 watts (NP 159). Both comfortably Zone 2.

Time breakdown by zones for HR - 2:55 in Z1/Z2 and 17:00 (low) Z3.
By power - 2 hours at Z1/Z2 and 1:00 above Z2

So my question is… does this really count as a Zone 2 ride? If power creeps into Z3, but I can keep my HR down at a reasonable cadence (not grinding a huge gear, lets say 75+ rpms)? I prefer to do my endurance rides on this type of route than having to stick on the boring flat lol.



My guess is that you were not holding long periods of time over zone 2 and not by much so it never allowed your heart rate to react to the effort. Power is instant but heart rate is not. You kept your heart rate in zone 2 so you FtFP’d. We say heart rate in this plan just so you don’t go too hard and put added fatigue in your legs before the more intense workouts. With endurance rides in zone 2 a lot of times your heart rate can come up over time putting more strain on the body even though your power is still zone 2.