Originally Posted by Squint
Lactate threshold is a lower intensity, around 2.5 mmol and occurs somewhere in L2.
I have to say this is inconsistent with the things I've read, been told by coach, and my own physiological testing.
First, its my understanding that LT, as measured by blood lactate, is not a set value for the amout of lactate, but rather the point at which the increase in lactate starts to spike.
Second, for practical purposes, power at LT is very equivalent to power at FT, if you define FT, as your 60 minute power. Most trained athletes can ride right around LT for one hour. Hence, LTP is equivalent to FTP.
I've had my LTHR and LTP measured in a lab, and then 2 days later done a CTS field test. My HR and Power at LT as measured in the lab was almost identical to my functional threshold power and HR as predicted by the field test.
My take away from all this, is with a power meter, you really don't need to know your actual LT, or have it measured in the lab.
At some point this becomes a matter of semantics and definitions. Rather than debating how many angels can dance on the head of a pin, the important figures are what you can do on the road . Hence working off your FT, as measured by a one hour TT effort, or the Coggan method (20 minutes reduced by 3-5%,) or the CTS method (92% of 8 minutes) is perfectly adequate for training, and arguably more revelant than a lab number.