Originally Posted by
Carbonfiberboy
It's simple: HR varies. What a weird test - I don't get it. If you want your FTP, hard warm up, do 20' on, 10' easy, 20' on, with the on intervals as hard as you can hold for 20'. Takes practice. Then take 95% of the best 20' average for FTP. Ignore your HR. That's the great thing about power - you're measuring effort not its physiological effect which can vary quite a bit. You could also take the max steady power you can hold for 2 hours, divide by .75. Or you could just ride as hard as you can for an hour and use that. I think it's too easy to get faked into using too high an FTP and thus doing all your workouts at too high a level and crapping out after a couple weeks of that. FTP isn't an ego thing, it's a way to keep you from overdoing it.
If you want to use HR, you need to find your LTHR which will be about at your FTP or ride continuously at what you think your FTP is and see if you go over LTHR and have your legs fail from lactate buildup.
Ramp tests are widely used for FTP. SYSTM adds the 20 minute subthreshold effort, ostensibly to 'refine' the FTP estimate. I think ramp tests are good for cyclists like me who haven't ever tried to do a 20 minute FTP test, and so have no experience with pacing etc. I used to use HR to train exclusively, till I got a Smart Trainer and started using power, but only on the trainer.
The one thing I'd say is the RPE was pretty much the same for the two ramp tests, both of which I stopped at the same 'feeling', but one was significantly higher power. Anyway, I found it an odd observation, such a difference in power at the same HR, and over a long enough interval to be 'real'.
FTP is also a way to keep you from UNDERdoing it.
