windschatten wrote:
I'd go by heart rate and RPE. RPE requires experience over the race distance, though. Most people with PM's can't do RPE...that's why they need a PM.I don't think your second sentence is true. Everybody I know with a PM will also factor in HR and RPE as well. Racing on pure power alone and ignoring what your body is telling you isn't something I've heard anybody advise. What a PM can do is really help you to calibrate/gauge your RPE better, by training and racing regularly with all 3 you'll have more tools at your disposal to pace you through a race than somebody who is relying on just RPE and/or HR.
The other problem is that IM is a relatively rare and hard to replicate event for most people, and that can throw HR and RPE off considerably. I know I never do a long swim then long bike in training, and it's pretty rare that I do century rides when fully tapered. I find RPE to be a pretty poor guide for the first third or so of the IM bike - the fact that I'm fully tapered, adrenaline pumping for race day, and nicely warmed up by the swim means that my RPE for any given effort level feels way lower/easier than it ever would on a training ride. I also find I can sustain a higher average HR when tapered and in race conditions than I ever do in training. Looking at both is better than looking at either one (since RPE is telling me I can go harder but HR is telling me to slow down), having power as well would be better still.