Just to throw one more option in the mix FasCat now has Auto FTP Detection
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Another piece of their new CoachCat feature, that got zero attention when I shared that a bit ago:
Itās a wonder why most platforms donāt offer CP modeling or āAuto CPā. All they have to do is borrow from a git repo and and integrate it like Stryd did.
Iām not sure how everyone else tracks their progress, but I use a CP trends chart that has my cycling history (only from 2018 til now) and compares CP, Wā, and CTL (based on Skibaās Bikescore). It really shows how inconsistently I ride.
I have a WKO5 chart that has mFTP (WKO5ās modeled FTP, similar to CP), my set FTP, and TRās AI FTP Detection to see how everything aligns. Plus how well does AI FTP āworkā for me.
TRās AIFTP continues to not work for me. Just got my next update after another 28days but it always tracks miles behind other approaches and itās so cautious in ramping up.
Old TR AIFTP 354W
New TR AIFTP 360W +1.7% today
But just in the last 28 days my training has included outdoor efforts on climbs of (just looking at over 360W and over 10mins):
17m at 419W
11m at 424W
18m at 407W
17m at 402W
17m at 400W
11m at 403W
11m at 396W
12m at 388W
25m at 367W
Intervals.icu currently puts me at 395W with 24,480J Wā. Intervals.icu has increased my FTP by 14.5% in the last two months as I regain fitness after the off season. It has found the right level throughout this period in my experience. This is night and day vs TRās caution as I rebuild.
My all time best is 408W with 21,525J so I still have room to grow. Which is exactly what happens every winter>spring>summer.
I get that getting good training numbers is top priority. But AIFTP just uses too much caution and appears to try and fit you to the middle of a bell curve, even if your past performances and trends would indicate a different approach would be more appropriate.
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Set your minimum time for eFTP in intervals.icu to 30 or 35 minutes and see what number it gives you.
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But I virtually never do a consistent effort of that duration, certainly not at max effort. Iām a crit and road racer first. If I do a TT itās a 10 miler and Iām prioritising speed (aero position) over power.
Thatās kind of what I thought youād say. Follow up question: whatās the most time in zone for a threshold workout youāve done recently, and what was the interval structure - eg 3 Ć 20mins at 98% of FTP?
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Send in a support ticket.
Whats duration does intervals estimate FTP off? Very rough stab at your figures doesnāt put AIFTPD far off. Say 0.90x400 = 360w. If intervals is looking at a max effort over short period it can be biased by a strong anaerobic effort and it sure sounds you are strong 
TR uses ftp to set all training zones. You would want it to be conservative so you donāt get everyone complaining about failing workouts. Just because you hit a power PR, doesnāt mean you should immediately scale up all training intensity zones.
If your 25min at 367 is a max effort, then it seems AIFTP of TR is quite accurate, as they are assuming the ftp is based around 60mins
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I think the intervals default is 5 minutes. It re-estimated my eFTP the other day based off a shortish effort and I just said āLol - nopeā and went in there and set the minimum time to 20 minutes.
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Iāve been riding outside and using climbs over the last block so itās not been structured quite like that. Itās been efforts during multiple 3-4hr rides. I can say that in the last 28days (inc a rest week) Iāve done 5.5hrs at threshold using Intervals.icu measurement. If I used TRās FTP that would likely be over 10hrs in the last 28days. Iām not sure if this is helpful though?
I exchanged messages with Amber on this a long time ago and she looked into it, but no answers came of it. Iāve not raised a support ticket since because I have other platforms estimate FTP for me
Yeah, no. 
Simple solution is to do a long form test or an open-ended interval. Get your RPE up to whatever threshold feels like and keep going.
If you have a big anaerobic contribution then a power curve extrapolated from short efforts can seriously overestimate your FTP. Weāre talking 30 to 40 watts over.
Of course, all this assumes that the number and its bigness matters. Performance matters more, right?
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Yeah, sorry, should have added Iād be curious to hear what TR had to say about this.
Yep, performance matters more and I just donāt have the roads for a 30-40min test. Way too many junctions or downhills as my roads are constantly rolling. TBH Iāve given up on AIFTP but still update it went I can to see if itās improving.
Iām normally a 8-11 hr/wk rider, wanted to take it easy and so in the past 10 days I road my bike 4 hours (including 30 min tte ride) with one ride having 2x10 tempo. I was itching to go hard again and wanted to do a 30 minute tte. I know itās not the 45 minute test, but I think itās close enough to feel out what I could hold for 40- 45 minutes and build off of that.
The ride yesterday 30mins @ 323 watts.
The estimated FTP from various sources:
Strava : 322
Intervals.icu : 316
AI FTP : 306
Iām surprised Ai ftp is the lowest of them all. Ai ftp is normally the highest of them all. 315 seems pretty accurate to me, intervals.icu is normally pretty spot on IMO.
I rated the ride āmoderateā, thatās how the overall ride felt. I didnāt associate it with any workout either.
Anyways thought Iād share this information and will see how 315 goes for the next couple weeks.
Iām not necessarily surprised by thisā¦ considering you said youāve āwanted to take it easyā latelyā¦ AI FTPD doesnāt just look at that ONE ride when determining itās calculation. I certainly canāt speak to how far back it looks, but have heard many times it looks at your ārecent training historyā when making itās calculationā¦ that ārecent training historyā is undoubtedly > 1 ride, so outside of this last effort, if many of your other rides were Z2 spins (for example)ā¦ those spins will likely all drive that calculated number lowerā¦
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Good point.
Like I said Iāll see how training goes since I start base 1 next week. Iām not afraid to lower my number if it means more consistent training.
Also I just read/learned that Joe friel recommends using the 30 minute all out power average as the number for someoneās ftp. I donāt know how I feel about that but he knows more than I do.
The next time I test myself Iāll try the kolie moore protocol again which seems most accurate, imo.
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