I’ve been using AI FTP since it was in beta and have always felt like it’s very accurate. However, today I experienced something odd and wanted to see what kind of insight others may offer.
One week ago (Thu 8/29), I did a ramp test. I like to do ramp tests the week before I start a new training plan, then I stick to AI FTP for the rest of the plan. Just personal preference and I guess I’m an oddball that doesn’t hate ramp tests. My ramp test gave me an FTP of 274, which I was quite happy with (right around my peak for my previous training plan this year). I started my training plan this week, and I did a V02 workout outside on Monday (Mound 1.5, 60mins) on my MTB, followed by 60 mins of easy singletrack riding. I didn’t find the V02 workout to be that difficult except for the last few intervals and debated whether to rate it Moderate or Hard and went with Hard (I’ve read it’s best not to overthink the ratings too much but I usually can’t help it haha).
I didn’t ride on Tuesday, just some light upper body strength work. Yesterday (Wednesday) I did a very easy 30min ride around the neighborhood after work.
This morning I had a sweet spot workout (Jordan 2.0, 60 mins on indoor trainer). I once again felt like it fell somewhere between Moderate and Hard, and I ended up rating it Moderate. After that, the TR app told me I had a new FTP available, and I assumed it was going to bump it higher than 274 since I had just rated my workout as Moderate, but it dropped it down to 261 (almost 5% drop).
I’ve always felt like AI FTP detection was solid and followed what I was feeling, but after a ramp test of 274 and two workouts that I didn’t find to be particularly difficult, I’m a bit perplexed. Does anyone know how to explain the drop?
TLDR: Ramp test last week gave me FTP of 274. After two workouts that I rated as Hard and Moderate, AI FTP dropped to 261.
I could be wrong but I don’t think you ratings have an impact on AI FTP. They may have an impact on adaptations. I think AI FTP is looking at what you’ve done and by that I mean your power curve. It seems odd that it wouldn’t also look at the ramp test result, but I’m guessing it’s not specifically looking at the ramp test result, but just the power curve of that ride as it does with any other ride and coming up with a new calculation. From the sounds of it, you haven’t been doing anything particularly difficult to demonstrate that 274 over the past month or whatever the lookback is for AI FTP. If a sweet spot 2.0 workout feels hard, then my guess is that you are (like many) leaning too heavy on your aerobic maximum (vo2 level) and not heavy enough on your aerobic base. Therefore you do well on your ramp test because it can be cheated a bit by a high ceiling, but that your every day rides and workouts don’t push you that high.
You are correct that I haven’t done much over the last 4-6 weeks for AI to have much to base an FTP on, but I assumed a ramp test within the last 7 days would weigh heavily on the AI detection. And to clarify, I rated my sweet spot 2.0 as moderate, not hard.
The ramp test is spot on (or there abouts) for circa 70% of people but will overestimate FTP for circa 15% of folk or correspondingly under estimate for circa 15% of folk. Perhaps you are in the ‘over estimate’ camp @TrailMix and the AI FTP number will be a better number for your long term progression. Looks like TR are investigating for you so hopefully they’ll be able to tell where you FTP value should be.
I could see this being the case as I have had a few surprisingly high ramp tests in the past, but it still seems odd that it could determine a 5% FTP drop after just two workouts rated Hard and Moderate.
Overall I’m not that concerned about this. I accepted the new 261 FTP. Mostly just curious as to what triggered the drop.
You may have answered your own question with this statement. I don’t know how far AI FTPD looks back in training/riding history, but I suspect this will weigh in pretty heavily vs just the ramp test and last couple workouts you’ve completed.
I have also seen an AI FTP drop in the past if I’ve been focusing more on just having fun on the bike vs true structured work. I’m not sure specifically what you mean by “haven’t done much”, but if it lines up with just noodling around or an extended break, that’ll likely be your reason.
I don’t think my sprint is terrible. I’m 79kg and my max sprint from a few years ago was around 1350w when I was doing more V02 work. It’s more like 1000-1100w here recently.
I should probably clarify more on the “haven’t done much.” I’ve done plenty of riding over the last 4-6 weeks, but most of it has been Z2 work. My A race was mid-July and after that I didn’t have much intensity. I wanted a break before I started my next training plan. I did one hard 1-hour effort on the MTB two weeks ago, but other than that I’ve been mostly tempo and below.
I’m not worried about it, simply curious is all and wondering if anyone had some insight. Like I said, I accepted the 261. If I was that concerned or thought it was wrong, I would’ve just ignored it and kept on with my workouts at 274. Appreciate all the feedback.
I’ve taken a closer look at this and while there were a few things that made this FTP update a bit confusing, I actually believe that the software made the right call.
As you already know, AI FTP Detection references a lot of data when calculating your new FTP whereas traditional tests such as Ramp Tests really only focus on one moment in time.
AI FTP Detection was prompted in this particular case because it had been 28 days since your last detection. This actually had nothing to do with your recent Ramp Test, or the results of those two workouts that you’ve referenced. It may have seemed strange to pass a workout and give it an “appropriate” rating only to have the software tell you that your FTP is set too high, but consider this with the understanding that AI FTP Detection has been gathering data to use for this for several weeks now.
As others have mentioned already there is a certain population of athletes who fall outside the bell curve of those who test “accurately” with ramp tests, and you could be one of those who typically test high. Alternatively, you could have just had a really good day during that test too!
My suggestion would be to continue on with the FTP that we assigned to you and see how things feel moving forward. Adaptive Training will adjust your Progression Levels as it sees fit and your workouts should adjust to your current capabilities.
It looks like this is the route you’ve chosen to go, and your most recent Threshold workout appears to have been a good one for you so I’d say that you’re definitely on the right track!
I hope this helps to clear things up for you. Just shout if you have any other questions though. Sometimes there can be a lot of noise packed into a small window of time which seems to have been the case here, but once you unpack everything and look at it all on its own, it does make sense.
This is so helpful, thank you! My first inclination is always to trust what AI FTP recommends because it looks at such a large set of data compared to the tiny snapshot provided by a ramp test, so I was just curious what may have led to this drop. My training seasons will probably look pretty similar to this going forward (a few months without much structure followed by several months of stricter training for an A race, then repeat), so I’ll keep that in mind should this happen again.
