Originally Posted by spelger

i am certainly no expert but i agree with this. i am upside down compared to the OP. i had a PM only because i had a smart trainer, i just got a HRM. i could have used it as a proxy for power but there is nothing like having the real thing to guage your effort by. however you the OP measures FTP i would do it, he can always adjust as you say.

-scott

i'll add that when out on the road i will need to use the HRM as a power proxy. with more use on zwift with power and heart rate i will have some good numbers to use as reference points.