Originally Posted by
asgelle
There are two choices to specify LT: power and VO2. Power is much more amenable to field testing.
Estimation of what? LTHR may be used as a surrogate for LT or functional threshold but that's all it is, a surrogate.
I don't follow. How do I find what for accuracy? I use functional threshold power for the purposes it was designed for. In races, I pace by strategic and tactical considerations. Usually, that means keeping up with the pack. On my own I pace by a combination of power and RPE based on the desired training level.
I have two friends just starting to train with power. I think I'm going to strongly recommend the don't wear a hear rate strap. It just tends to needlessly confound things.
My understanding is that there's just one choice to specify LT: "Lactate threshold (L T) is identified as that point at which a 1 mmol/L increase in blood lactate concentration above baseline values is followed by another 1 mmol/L increase." >
http://www.coachr.org/lactate_thresh...erformance.htm
Some authorities say LT occurs at a 4 mmole increase, others at a 2.5 mmole increase. The above quote identifies the lower threshold, which seems like a good idea. In any case it has nothing to do with a particular power or HR, but with lactate accumulation. We can use power or HR to estimate current LT, but it's only an estimation. LT moves around quite a bit during our training year, both in terms of power and HR. LTHR is a surrogate and so is FTP.
The tremendous advantage of using both power and HR is that it allows one to precisely determine one's momentary physical condition. If your HR at 270W is 180, you know you got a problem, and you might also know the solution. Same with 270W and 170HR. Without the HRM, you're guessing at the problem; in both cases you know something's wrong, but you can't be sure what. It does make things more complicated, because it gives you something extra to understand. Every tool we use requires some thought and experience to use well. RPE isn't nearly as informative, especially in the early stages of things going sideways.
I'd use both if the PM weren't so expensive. I just can't justify it, so I use cog-and-cadence and RPE vs. HR. Not as good as power vs. HR, but it's close enough to be able to train and ride efficiently.
I come at this from a slightly different angle than you, that of an LD rider. Sometimes I have a pack to keep up with. Much more frequently I'm pulling a paceline with or without help or riding solo. It's like I'm always off the front by myself or with 3 other guys. I'm much more interested in fighting environmental problems, both exterior and interior, than in FTP. If I take care of my personal environment, my performance will be what I'm able to achieve through training and nothing else. My HRM gives me a decent window into that environment.