What is the rationale behind 20 minute FTP test power target?

One thing that I have never understood about the 20 minute FTP test was the target power during the actual 20 minute test. The interval target is 102% of FTP.

In my mind, what would make sense is having the target power equal to whatever value would result in equaling your current FTP.

For example, your FTP is calculated by taking 0.95 * (20 minute test NP). Say you take the 20 minute FTP test and have an NP of 211. Your FTP would be 200. The next time you take your test, the target power will be 102% of 200, or 204 W. This number seems meaningless to me. If I were setting the target power, it would be 211 watts (~105% of FTP), making it easy to see how you are stacking up to your last test and give you a meaningful number to try to equal or surpass.

Something I’m not getting here?

I think you’re missing the point. The target is irrelevant. You need to be familiar with the feeling of an all out 20 minute effort, you’re not shooting for a target power, you’re shooting for a max sustainable effort for 20 minutes. Shooting for a specific number in the 20 minute test is a pretty good way to get a poor result.


You take the average power not NP

The target is useful but for pacing only; you want at optimum to gradually exceed it and then finish all out to raise your FTP.

I tend to agree that a “target” of 105% ftp might be more useful for pacing - not sure of the rational of choosing 102%.

But to be honest the whole concept of a 20 min test is a little flawed in that regard - if you know what the target is then what is the point of testing at all.

It’s an all out 20 minute effort. The target is irrelevant, but the line can be helpful to gauge how steady you are holding the effort. When I was using TR I would cover the current power and the graph, and only pay attention to the time. Once you’ve done the test several times you begin to know what a sustainable all out 20 min effort feels like in RPE, and the result will either be a nice surprise or a “back to the drawing board” :crazy_face:


i agree with the others here; might be splitting hairs a bit much. Just rip it!!! and let the numbers fall where they may.


Important takeaway from your post is feel. The more one does it, the easier the feeling should be. Problem, I guess, would be that some just don’t like doing it and prefer to estimate it using a shorter duration.