New TR feature - FTP estimate - thoughts

Coggan’s definition is clear, he came up with the term and its his definition. Coggan gave examples of different ways to estimate it. And that’s where the problem begins - you either a) read about FTP secondhand and come to believe it requires some specific test protocol that must be followed exactly, or b) you accept the definition is inherently fuzzy, the estimate is subject to multiple sources of error, and there are many ways to estimate and correlate one result to results from other estimation methods.

Those who’ve done ‘more exact’ tests will tell you the human body exhibits time varying behavior. I’m of the ‘just go with it’ camp, accept its an estimate with a margin of error, and treat an FTP estimate as a range not a single number.

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We are in complete agreement on this. This was my point: talking about more “accurate” FTP estimation methods doesn’t make sense, as there is no gold standard for getting a “true” FTP for anyone. So you cannot compare different estimation methods and say which is inherently more “accurate”.

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Nothing like a good ‘what is FTP’ thread on a cycling forum :rofl:

There are two things that are often conflated:

  • What FTP is - ie the definition of FTP
  • Ways to estimate/determine FTP. There are many different ways to do this with different tradeoffs.

My take is that it is relatively clear that FTP “is” power at MLSS/LT2. MLSS is the physiologic ‘quasi-steady state’ that is talked about and that FTP is tied to.

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But it depends.

For me, FTP as modeled by WKO from CP testing (20s, 1m, 4m, 10m, 31m max efforts) is basically CP. 3-parameter model in Golden Cheetah gives me a similar value. My TTE at CP was 31 minutes. My blood lactate was raising throughout the entire 31 minutes. However, my VO2 was steady.

My MLSS is likely 15-20 watts lower than CP and FTP model estimates. But I’m a sprinter phenotype and have a poor threshold/max ratio and TTE at threshold.

I think they use the intervals.icu uses the same calculation, which is something like 75% of your best 1min average power.

Mines are always close too.

Not in this case. See the part I circled above. They used the 6m30s effort specifically in this case.

Couple that with the fact that I set the eFTP Minimum Duration to 6 mins (360 secs), I should never get any eFTP changes based on times less than this setting. So there is no way the ICU one is using a 0.75 x 1-min effort for me.

image

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Is that from your ramp test ride though?

Surprised this is still a topic of discussion. ‘FTP estimate’ is not a new feature request, it has been implemented already. Progression levels are the FTP estimate. Just change your FTP manually and see how the PLs change. Shared the graph below in August, for me (and probably for everybody else) a SS PL of +1 can be translated to +2.8% FTP.

TR4

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Yes it is. But the eFTP as detected by ICU clearly shows it give the estimate based upon the 6m30s max of the test. It is interesting to me that I got the same “FTP” value from TR with their method (0.75 x 1m max), and the ICU uses some different time period and multiplier (around 0.84 x 285w if my reverse math is right).

No major claims, just “interesting” as I have said. This is a different comparison than the other eFTP that I have had from ICU that came from different workouts, but closely paralleled what I knew about my FTP at those times.

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have you done a max effort of greater than 360s that would result in a higher eFTP? In theory the TR ramp pacing for that time period may underestimate such an effort.

Commercializing an idea old as dirt (just like the ramp test, not really a TR novelty). I like the idea that some workouts will yield an ftp update. I don’t know much of what TR is doing but basically will see response to some FTP probing workouts. I don’t understand how that is going to work with ERG mode : I typically do 4x10min’s all out and take the avg as an ftp update (try it, you’ll see that it’s darn close) but in ERG their wouldn’t be a way to over do it…

  • Nothing close to that in the last 6 weeks.
  • Agreed. That’s partly why I was surprised to see a value flagged like that.

At least some of this probably comes from the longer than usual break I took in Oct/Nov, which lead to big drops in actual and eFTP. So this trigger here may be a result of no other significant efforts in that timespan.

For reference, here is what my fitness graph looks like over the last 3 months, if it’s useful:

Considering how the ramp felt and how my training was going leading into this test, I actually think the 240w is quite close for me vs other tests where I knew something was “off”. I will get a better feel with workouts this week, and evaluate just like I usually do.

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Xert has “smart workouts” that are meant to not be completed to dial in your fitness signature, if TR started plugging in some say PL+5 workouts as a preassessment they could maybe get at a good estimate, but users should be aware they aren’t meant to be finished

TR gave me 258W on this ramp too.

Both over inflated imo.

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what is you eFTP calculation duration set to?

Just checked, 180 sec

Try bumping it to 5+ mins, works better for me if I think it is setting my eFTP too high

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Ditto, I had some inflated estimates when it was at the 3m default. But that is at least partly due to my apparently good short power. So might not be a problem for everyone.

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I just changed it to 300s and ride eftp is same, but my overall eftp has dropped……1W :rofl:

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you could try changing it to the morton 3p CP, mine is about 20-25w lower than my eFTP but TTE jumps about 15 mins longer

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