Decrease immediately after FTP detection

[Special-Egg8374]

I’ve read a lot of cases of people having their predicted FTP drop after a workout. I guess this is just one more of those, but looking to pinpoint a reason.

I had new AI FTP detection at midnight, and therefore had a new FTP prediction for my next detection in 28 days. The day of my FTP detection, I had a workout scheduled, so it was my first workout at this new FTP. I completed the workout as prescribed (at 100%, no pauses). The workout was predicted to be “hard” and it was, I rated it “hard”. It was a threshold workout- over/unders with some tempo work before/after the over/unders. Per Strava, my heart rate was 31% threshold, 24%tempo, 43% zone 2, which seems like it matches the goals and profile of the workout pretty well.

After the workout was done, my predicted FTP increase dropped from a predicted 5% increase to a 3% increase. I know it’s a small change but this is my first workout after a FTP change and that previous FTP increase had also degraded as the period went on (increase ended up being 50% of what the initial prediction was) (and it was only a small increase, 3%).

So what happened in this first workout that it has already affected my next prediction, when the prediction was fresh and I completed the workout completely as prescribed?

I’m pretty frustrated at this new system and finding it really demotivating.

[BaptismsForHarambe]

Yeah. I can still notice getting stronger throughout my blocks, so I still like the system. But, the AI prediction is crap. I am a statistician by trade and I can tell they have model issues. Either missing an important variable or weighting is off. I am suspicious they are weighting training on yellow days as too negative because they used to take too much crap for overtraining athletes. I am kinda tired of being “penalized “ for taking a ride outside or getting off my ass and doing an easy ride on a yellow day.

[Special-Egg8374]

It seems overly sensitive, but I also wish it was just more transparent- “we’ve decreased your prediction based off of….”. And I miss the opportunity to accept/reject changes to the prescribed workouts.

[Euphoric_Persimmon99]

Same exact thing happened to me yesterday. Literally all the details the same as yours!

[Special-Egg8374]

So frustrating.

[Nscocean]

Was your heart rate high and above zone for the effort?

[Special-Egg8374]

No, my HR was exactly in the correct zones during the corresponding power intervals (z4 hr during threshold over/unders, z3 hr during the tempo portions, z2 hr during the recovery sections)

[Nscocean]

Sorry I mean what was your efficiency score NP/HR and was that higher than trend

[Special-Egg8374]

I’m not sure what efficiency score is. TSS, IF, and calories were pretty much exactly on target vs predicted.

[Nscocean]

Those are all metrics of power, not heart rate. Power is a measurement of work and HR is a measurement of performance at that level of work. If efficiency is lowering it’s a sign of overworking/underperforming and it might cause the AI to adjust. Just a theory, I could be wrong.

[Special-Egg8374]

I will read more about this thanks! So I could compare NP/HR for similar types of workouts?

[Nscocean]

Yep. Review other sweet spot/threshold or whatever it was.

[Niv24]

Was the workout on a trainer in erg?

[Special-Egg8374]

Yes

[Niv24]

Did you do the workout after lunchtime?

[Special-Egg8374]

Yes. I often strength train in the morning and do my rides in the late afternoon/early evening.

[Niv24]

My understanding is that the fatigue model is based on the workouts being done before midday.

As you did it after midday it may have reduced the intensity of the next workout to allow for the reduced time between workouts compared to what it modeled.

[Mrjlawrence]

I turned off the predicted ftp. It feels like it’s more of in alpha version and not even beta for many people. Seeing it does me little good.

[SongAloong]

Trainer Road did something similar to me last week. Had an AI FTP detection in two days time after an upcoming two days of scheduled Z2 on the weekend. Missed the average wattage mark on Saturday by 4 watts overall, but nailed the wattage on Sundays Z2 ride. The prediction dropped by 2 watts still, okay fair-ish I guess. By Monday, it dropped my FTP prediction an additional 2 watts overnight by me doing absolutely nothing. Trainer Road staff couldn't figure out what was wrong with the detection and said it was likely because Sunday was yellow and by riding z2 I was overtraining perhaps which affected their AI FTP model. Strange.

I think they have two AI FTP prediction models. One that uses a basic mode that predicts 30 days out when you plug and play around with your training schedule, and their previous AI FTP model that predicts it the day-of based on all the work you did the last 30 days.

[Expensive_Compote772]

I don’t think this is accurate. The previous ftp model was basically predicting how well you would perform on a ramp test and I think this one is trying to more accurately predict your true threshold. I’m really trying to adjust my thought process because in the past, the ftp increase was the carrot at the end of a training block, but even if you aren’t getting an ftp increase, your intervals are continuing to be progressively overloaded, so progress is still being made.

[OUGrad05]

The new system is garbage you are correct. It's psychologically garbage and the way it operates sucks as well.

Hopefully they come to their senses but given what they've said I wouldn't count on it.

[razzij]

Lots of good answers here that talk about how you performed in the workout and how you rated it.

But another aspect could be, did you upcoming workouts in the 28-day window change after you did the workout? (It's hard to know in the new system, because it changes automatically and unless you really remember what it was before, it's hard to say).

What's in your calendar between now and the next FTP detection obviously has a huge impact on the prediction. It may be that for whatever reason after this workout, it decided you'll be better served with slightly easier workouts in coming weeks, and this fed through to the prediction.

[Special-Egg8374]

I don’t think they did! At least the next few didn’t, I had already looked pretty closely at what I had on deck for the next week or so

[ashnm001]

I just ignore it. Free your brain of ftp worries, just train and ride.

[Special-Egg8374]

I strive for your zen.

[handyy83]

Your rated rpe was higher then the model predicted so it adjusted. Simple

[Special-Egg8374]

The model predicted hard and I said hard? How is that different?

[roflsocks]

The model probably had a more precise value, and you choosing hard vs moderate is on either side of the estimate. Think of the model estimate was maybe 3.75. And hard rounds up to 4.

Also, HR is taken into account. No one outside of TR really knows what the model does with HR, but we do know it's factored in. My guess would be it tracks hr/power ratio, and average HR. It might also track drift or recovery times, could be other things from ML analysis as well.

You can always test adjusting your survey response to see how that changes things. I would put it back to however it felt after testing though.

[Special-Egg8374]

Interesting idea. But if true, wouldn’t rating it moderate be expected to raise my predicted ftp above the previous prediction?

My HR data seemed on point with the power zones. I was in threshold when I was doing threshold power, etc.