I was reading an article on Escape Collective today about various FTP tests. And in it they talked about the 4DP test and had some quotes from Neal Henderson who devised it. In the article they mentioned for a 20 minute test, to do 5 minutes all out first, then do the 20 minute test and take 95% of the total. But if I have it correct, in the 4DP test it takes 100% of your 20 minute test following the 5 minute effort? Anyone got thoughts on which is preferable? Still taking 95% of the 20 after a 5, or 4DP’s 100% of the 20?
4DP also does 2 full-out NM sprints, then a 5 min effort, then 20 minutes. That why it takes 100% of the 20 minutes.
That’s different than 5 minutes before 20 minutes. And different than a straight 20 minutes.
And still they’re trying to be catch-all tests. And still not everybody fits their numbers in exactly. And you could do 60 minutes and still not get a perfect number.
For SYSTM tests, do either FF or HM because that’s what the workouts are designed around.
For any other workouts, use what works best for you or what those workouts are designed around.
Whatever you do, just keep doing the same test. That way no matter where you fall on the spectrum you know your comparisons are accurate.
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@veloricky As @emacdoug notes, the two sprints at the beginning of Full Frontal are the reason. See below for a good overview - specifically the paragraph on the 20 minute test.
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I have read that the reason for the 100% of the 20 minute value is because of the 5 minute MAP effort. That is supposed to exhaust your glycogen stores so that your effort only/mostly comes from fat oxidation.
Yep, but on this article they state to still do the 5 minute effort but also take 95% of the 20 minute. But as a few mentioned above, the 4DP is factoring in the two max sprints also - though I find that somehow hard to believe it depletes 5% of your threshold power for the 20 minutes, but I suppose each person is different and without blood lactate work, you’d never truly know.
That said, I go with the 4DP results and I’ve had no issue with them. Perhaps it is a touch high as I’m not certain I could hold my 4DP 20 minute FTP for an hour, but then again, I don’t really have to. Perhaps and Alpe d’Zwift effort at FTP to see if I can hold it!!
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The workouts in SYSTM are calibrated with the 4DP results, so for the SYSTM workouts the 95% rule is not meaningful.
You cannot compare the 95% rule test with the 4DP test because they are measuring different things.
The idea of FTP is an abstraction that is related to, but different from biological reality. It is also somewhat related to real world performance.
Also note that FTP’s definition has changed somewhat. This is often designated as mFTP, and recognizes that TTE (time to exhaustion) at threshold varies by individual and fitness level.
“mFTP is the model-derived highest power a rider can maintain in a quasi-steady state without fatiguing.”
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