Not understanding TP

My current FTP by other measures is about 240. Xert is giving me a TP of 206. I thought Xert TP was the same as FTP. Am I misunderstanding TP in Xert? Or maybe Xert is a more realistic measure?

TP serves a similar purpose as FTP of course, but it isn’t derived in the same manner.
The numbers closely align for many users, but not always.

Threshold Power is a parameter of your Fitness Signature that represents the highest power that can be sustained without accumulating short-term fatigue – e.g. without MPA decreasing.

When you look at your XPMC chart over the last 3-6 months, how often are BT events (circles) shown?
When was your last BT?
What is your current status stars count?

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Ok. I see. Have a lot more reading to do to understand Xert. I’m still using other platforms while I get used to this and decide if I like it. I synced activities from long before I started Xert and see that my TP was 242 and two hour 232 last July when I was fit. It was sort of downhill from there and now working my way back. I’ve had some good efforts recently but I guess Xert is just a little more particular. Also live in an area of punchy hills where I’m either well above or well below FTP. Maybe Xert wants something more sustained.

A quick way to validate your signature (when you’re feeling fresh) is to ride this 30 min Breakthrough workout in Slope mode (not AUTO) using gears/cadence to attain targets.

That’s two all-out short sprints (7 secs) plus four escalating VO2 max intervals to draw MPA down.
Total effort time is less than 10 minutes.

Exceed targets if able and make sure to ride to a failure point on the last interval extending the duration as necessary. That’s why you want to ride it in Slope mode so the intervals are not under trainer control.
If you’re up for one more sprint, right before you are about to fail, spin up (stand if you want) and try to sprint for at least 5-7 secs before collapse.
This is the type of effort (indoors or outdoors) that validates your signature in Xert.
If a BT is detected your signature values will adjust. The numbers will also fluctuate moving forward based on your training load and intensity but it’s occasional maximal efforts under fatigue that confirm your signature is dialed in.

Lots of newbie tips in my Onboarding post if you haven’t seen it already –
Onboarding steps for Xert Trial users and newbies - General - Xert Community Forum (


Outstanding. Appreciate it.

I have as well a problem with TP and HIE, when it comes to breakthrough.

Quite often when I reach a breakthrough my TP is increased a lot (by 20 - 30 W) and my HIE is decreased accordingly. This then leaves me with a signature I can not sustain on the trainings as my FTP is a lot lower.

So I always reset my fitness signature manually just to make sure workouts match my capabilities. However, this is clearly not the intention and is rather against the whole idea.

So to go with real numbers here. Yesterday I had a breakthrough in a Zwift race, sprinting over the finish line. My FTP as calculated by many platforms is somewhere around 260-265 W - so I set TP to 262, and when I set HIE to 24.2 the MPA touches the Powerline on the graph. XERT came up with 285 W yesterday and reduced the HIE to somewhere around 17.

I’m not able to sustain any training with a TP of 285, I know that from trying. (I mean I’m fighting very often with the WO here anyway, as the suggested ones are usually too hard to find the motivation to do them, but that’s a different topic).

So what can I do, to get TP and HIE values that really reflect my capabilities?

Adding to it after today’s rowing workout:

This is what my rowing workout did today to my XERT-values. It doesn’t make sense to me, because I know that I can push beyond FTP quite some time but I cannot sustain a level that high (206 W) for 20 minutes, not talking of longer times, what TP would actually suggest.



You need to do some sprints to update peak power. Or manually update (e.g. if you are injured) e.g. to 800w (just a guess).

There is a strong correlation between PP and HIE so with a with a PP of only 330w it assumes your HIE is also low. And then TP must be high to ‘balance’


It is not advised to mix power data from different activity types under one profile.
You can create up to three profiles under one account.
For example, cycling, rowing, and running.

Max sprints at the line that draw down MPA but end abruptly (vs natural failure) are known to cause issues with BT calculation.
You could flag those activities when they occur which retains strain score but excludes them from sig calc.

I am using three different profiles - the exact three you mentioned :slight_smile:

But I guess the second thing you mentioned is the thing that’s happening here. Both in the sprint at the race it ended abruptly and in the interval, when it was done, it ended abruptly as well. Flagging all these activities will draw down my signature over time, and it will never adapt to reality. Not sure how to handle that correctly :frowning:

Do you occasionally ride the BT workout mentioned above or any of the other “fitness test” workouts in the library?

Uusally not, but I think keeping the MPA reasonably high, before clicking on extract might do the trick. I tried i twith the rowing workout above and the results seemed to be sensible.

Yes, that will do it but if you want to prove your PP number (for your cycling profile) all you need do is spin up, stand if you want, and stomp/pull on the pedals as hard as you can for at least 5-7 secs.
A “fitness test” workout (or any workout with sprints in slope mode like this one) provides the means to do that.
This helps keep your signature in check even though indoor PP is typically 100 or more watts lower than outdoor PP.

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Thanks a lot. Put it to my favorite WOs.

This is a very good suggestion. Thank you!

I don’t know anything about rowing but I usually have the same problem with my riding breakthroughs. The TP goes well beyond what I think I can sustain and the HIE goes down and that makes the LTP go even higher and any hope of doing Lucy without gasping for breath after 15 minutes with the new signature goes out the window. And that makes one hate breakthroughs or at least the frustration with unrealistic values afterwards.
So then I either flag the breakthrough or manually adjust and extract.

I just had two breakthroughs (one week apart, same spot outdoors) with just that happening after having started training again mid December (TL was 2 is now 15, indoors, LTP endurance only until last week). I now tried the suggestion to up the value of my PP and extract and the resulting signatures are way more reasonable. I just don’t know how high to set the PP now, and it feels like cheating :wink:

I never sprint on the bike, don’t really know how to (technically). I can’t spin standing up, probably fall of the bike trying, I usually ride with a cadence of 70-80 or even lower. I’m a recreational rider at best, middle aged and overweight but I’m also biologically the sprinter type, always have been with all sports. I have no endurance and never had much but I once was quick to start and could sprint faster than most of my classmates as a teenager when running (50m sprint) or swimming (25m sprint) while I failed miserably at running/jogging 1km at all even though I was an active Judoka at the time and thought of myself as reasonably fit.

My breakthroughs are usually efforts of a few minutes (the recent ones about 4 minutes) always outdoors with short breaks to get some air back. I think those express my HIE but Xert always wants to give me more TP and less HIE as a result.

These are the ones from a week ago and yesterday, just the breakthrough part. It’s a longish ramp, plus a short downhill plus a flat part afterwards at the end of my commute to work that I occasionally do by e-bike. I use Assioma duo pedals on an e-bike so that’s unusual but the watts produced should still be the same, it’s mostly ridden slightly above the speed limit (25kph) of the motor. I’m still fresh when I get there because the motor helps while riding slower and I get back home easily in the evening when already tired. I’ve had exactly the same effect on my road bike (also Assioma duo but no motor and a third the bike weight) as well, I do 3-4 minute efforts and get a higher TP and lower HIE :frowning:

HR maxed out at 175 and that’s pretty much my max for cycling, maybe a few beats more but not much.

I was not fleeing from an angry bear, I just pushed it for the last bit of the ride, so I might have been able to do a bit more but I’ll probably never encounter that bear and thus never find out :wink:

As a disclaimer all of you have values much higher than mine: My TP is around 95-125w, my HIE around 9-13 and my PP I have raised from 450w to 550w with 470w being the best 1s my Garmin has stored for me. Best 5 sec is 426w last year, best recent 2 min 170w and 5 min 132w both somewhere in those two breakthrough rides all from the Garmin power curve readings.
Both my Assiomas and my Tacx Neo seem to produce relatively accurate data.
I’m female, 48 years old, BMI 29 and mostly sedentary with occasional bouts of riding or swimming but mostly just walking a few times a week.

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I think you just need to use trial and error, all out for 10 seconds or so… and you don’t necessarily need to stand… but for safety you want to have a quiet road and enough space

Try from a standstill… or spinning up from endurance or tempo pace… try low gears and high cadence (apparently works for most) or heavier gears

That said, I’ve never tried sprinting on an e-bike, and can imagine it’s different… but again I’d use trial and error

I do have a good road bike as well, I can try sprinting with that one. Maybe when the weather is a bit nicer. I’m just not sure how to get from low to high that quick pedaling, sprinting for 10 seconds never felt useful on a bike. Might be quite different when racing but I never did. I know that I’m bad at spinning fast since I naturally never do it and I did some indoor spinning classes years ago where I sometimes felt like I almost fell off the stationary bike when we should spin fast while standing, just feels very uncoordinated for me, clumsy. Like my legs are too thick and heavy to move that fast and I feel like loosing control of the momentum. Just like nothing I’d like to do on purpose if I can avoid it.

I got the e-bike for the commute 5 years or so ago since I often wanted to bike to work in the morning but almost always dreaded the ride home in the evening and thus often did not take the bike at all to avoid that. With the e-bike I can go as hard or as easy as I feel at the moment and thus it is much easier to commit to. No matter how easy I pedal with the help of the motor I still arrive more or less in the same amount of time, about an hour, by car it is about 35 minutes or more depending on traffic. It’s close to 20km from home to work and since we have home office I mostly only go once a week now. And weather and other factors permitting I try to go by e-bike. It was pretty chilly and windy these two times but there was no snow or ice and I was motivated for once. Have to use that whenever there is motivation to be had, I’m rather lazy by nature.

May take some practice, and would definitely do it outside as it’s completely different than indoors (the bike can move under you from side to side, and you can put out more power)

Also, you mention spinning and I wouldn’t really call it that when sprinting…I probably shouldn’t have said ‘spin up’ above… cadence can be very high, but the gear is still hard with a lot of force going through the pedals… shouldn’t feel particularly unstable once you get used to the bike moving under you. If you pedal with too low a gear I can imagine it feels unstable though - hence, trial and error (somewhere safe)

One other suggestion: practice up a bit of a hill, but already carrying some momentum I.e, sprint from the very bottom from a decent rolling speed. The hill will add resistance and make it less likely that you spin out. It will also keep the speed lower, for safety, especially if you’re not confident.

You can of course make up your peak power… if you’re not a sprinter type, maybe 3 times your FTP… but you are then missing out on one of the selling points of Xert I.e having a signature and workouts tailored to you… of course by not having an accurate signature today, you are also not benefiting fully from Xert. Whether you care depends on objectives etc.

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