My rhetorical question was prompted by the following article on TrainingPeaks.
I'm well aware Andrew Coggan has made it clear many times that TTE is not as accurate as some of his other metrics.
My point is that it would seem TrainingPeaks and some of their coaches do not understand the impreciseness of TTE and may be misdirecting training because they think it is a useful metric. We now have an article posted on TrainingPeaks giving complicated methods of estimating FTP and quoting TTE as a useful metric. They certainly give the impression TTE is an accurate measure of how long one can maintain power at MLSS.
There is a danger that people self coaching or coached by those who put too much store in TTE could be seriously misled and they should be reminded of Andrew Coggan's seven sins.
Here is the article.
https://www.trainingpeaks.com/...w-testing-protocols/
Many popular training methods today are aimed squarely at improving 20-minute power. While improving 20-minute power can be a sign of progress, we don’t know if we’re truly increasing FTP, which is the amount of power that can be put out at maximal lactate steady state (MLSS). While in this state, an athlete will fatigue in between 30 and 70 minutes (known as time to exhaustion, or TTE)1 rather than the traditionally defined 60 minutes. It’s easy to see that FTP is not always 95 percent of an athlete’s best steady-state, 20-minute effort. In WKO4, the Aerobic Anaerobic Contribution chart will show us how power at 20 minutes can be different relative to FTP. This chart is pictured below for a well-rounded elite female road cyclist, and we can see an 11-watt anaerobic contribution at 20 minutes with a power of 279 watts. Her FTP of 268 is 96.1 percent of this power, and she can hold it for about 40 minutes. The second chart below is from an elite male track racer. At his 20-minute power of 262 watts, there is a 24-watt anaerobic contribution. His FTP of 238 watts (at a TTE of 75 minutes!) is 90.8 percent of his 20-minute power.
AlexS wrote:
Trev wrote:
Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing? Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?
As has been explained to you ad nauseam, the power-duration curve at these durations is very flat, such that normal day to day variability alone can result in quite a sizeable change in TTE attainable for a given power output. This is normal.
It can also be the result of a change in fitness.
Have a look at a few decent MMP curves and calculate the % variance between ~30-min and ~60min power (being a 100% increase in duration). You'll see that it's like ~5% difference in power, or something of that order.
So it stands to reason that even a 1% change in power output capability (well within day to day variability levels) can result in quite large differences in TTE (e.g. 10-12 minutes) at power levels at/near FTP.
Which is why TTE isn't quoted with any great level of precision.