Originally Posted by
Metallifan33
I don't have an outdoor PM, but I just got a Tacx Neo 2T which has a built in PM.
These are my numbers from my 20 mile, 1hr 15min ride yesterday:
AW Total Calories - 873 (workout + calories I would have burned if I didn't workout)
AW Active Calories - 743 (workout only)
PM Calories - 501 (I'm not sure who's algorithm this is... i.e. Zwift, Strava, or the Tacx?).
So yeah... quite a difference.
On the other hand, I've tested the AW HR against my Garmin HRM and they are pretty spot on. I've even tested it against a HRM at a gym and the AW is always the same as others.
1:15:39 hh:mm:ss @ 116 W is 526,524 Joules delivered to the power meter. Strava estimates 501 kcal consumed by your body, or 2,143,000 Joules. This yields an efficiency of 24.5%, which is right in the normal wheelhouse. I think Strava is giving you a very accurate number for calories burned, within the limits of what is reasonable/feasible. Heart rate is simply not a reliable measure of calories burned. I can increase my HR by 20 BPM just by drinking a bunch of coffee or riding when I'm under a lot of stress. It's a great measure or perceived exertion, however. And units of power produced for a given heart rate can give you a good idea of overall fitness/fatigue.