Another one today. Meant to be low intensity but had fresh cleats giving a more planted feeling so decided to send it and see what I could do.
Only downside is my TP dropped even further and my LTP is now only 130! Which I donât really believe.
Whatâs the best way to try and address/ confirm? Email support, ignore XFAI for the next long-ish ride and just go for a ride where I push hard non stop (or Zwift race even), sprint and hold again but go until I drop go above MPA as well?
Lower Threshold Power - Iâve been following mine during my trial period as well. And what is slightly bizarre is that I already had a long term power setting set for when I was doing long indoor rides (eg endurance things for a challenge type thing) recently.
I realise thatâs not anything clever - soon work out on zwift or sufferfest (or whatever) what is âokâ to hold for a while.
What did surprise me was I started Xert a fortnight ago and it suggests my LTP is only 3w different to what I use.
Amusingly - I was wrong the last time with mine. Way over estimated mine - once I get to 5-6 hours I canât hold that number at all, it tends to drop 20% or so at least.
And Xert is over estimating too by the same margin.
And of course weâre all different.
But it is interesting both Xert and I thought it was the same.
Just another data point, as Iâve been examining similar data myself.
LTP is a calculated value useful for training purposes that aligns closely with LT1 for many users.
Itâs not a ride-all-day number.
When was your last BT?
You can flag the activity to remove the signature calculation and retain the strain score.
Then go out and prove your sprint power with a specific sprint workout. For example, 20-30 sec all out efforts with ample rest-in-between. Repeat until you canât do one again. 
Or ride one of the âfitness testâ workouts indoors in Slope mode to test sprint power and max power possible under fatigue.
It is not unusual for sprint power outdoors to be 100-200 watts higher than indoors. You canât thrash your bike indoors like you can outdoors.
Could also be magic cleats. 
Last BT was about two weeks before this one.
I donât doubt the new peak power, or the one minute power from this effort (if anything they could even be a touch lower as I felt hamstring twinge and reigned it in)
Itâs more the impact these last two BTs are having. They have roughly doubled my HIE, while dropping my TP ~10 watts and LTP by 40 watts.
Thinking about training the advice to ride at 130 watts it would be a pretty easy effort considering 3 weeks ago when LTP estimate was 170W it felt good. If my LTP is above 130 too as I suspect it might be based on RPE then when Xert says Iâve accrued 120 XSS on a low intensity ride at 130 watts, if itâs closer to 155-160 then Iâll be doing ~20% less strain than needed to improve.
So whatâs the best way to breakthrough or confirm TP/LTP? As recently I only really seem to be able to get HIE/PP BTs 
(last BT that increased TP was May last year, possibly before I even really started using Xert.
The extraction algorithm does itâs best to infer how much your TP, HIE and PP change from the breakthrough and it works well a majority of time but sometimes, especially when there are bigger changes, you can experiment with different signatures to explain the breakthrough effort. Open the Activity Details page and scroll to the bottom and try different signatures and see if you find one that better represents both the effort and your own sense of where your signature should be. In this case you can try raising TP and lower HIE a tad, click Refresh and see if thatâs better. When you find a good signature youâre happier with, click the Save button. Often times, this is less effort than having to go out and get another breakthrough. 
Itâs also important to note that if youâve never hit the peak number before, or come close to it, it may be data error.
Helpful again - so LT1 is approximately 3hrs, maybe 4, depending on models. Ok, that makes more sense. Iâd checked the help info first, honest ! which made me think this was the power after 4 hoursd and âforeverâ as it in theory means youâre just down to what you can produce from fat - but that was just my reading of it - your links confirm otherwise
Lower Threshold Power - XERT definition
How many BT circles are shown on your XPMC when set to a Year?
The signature calc update released in November does mean less BTs when decay is set to Optimal with tighter tracking of TP to TL.
How much has your TL varied in the last twelve months? (low to high)
When set to a year there are 7, mostly small. My decay is set to small decay (I remember reading that if youâre doing lots of zone 2 without pushing for BTs regularly that or even no decay is probably best)
Lowest TL was ~24-25 (post September work trip for 3 weeks)
Highest TL was ~54 (Mid Vol TR Polarised Base starting out prep for the ~510 XSS event in October)
And then here is a screenshot for âforeverâ (aka back to about 2022 for sync purposes; turns out I had a chunk missing from April to September 2022 but imported it now) in-case it is useful context for showing a longer period of TP vs TL.
Would love to know if this is normal; or looks iffy; happy to start a new thread or contact supportâŠ
Edit: I just realised that importing that 2022 chunk has led to changes in the past year BTs. Now looks like this.
In general, Iâll get suspicious when I see a few small breakthrough circles. I would examine each to see if they are a good representation of what you were feeling. In your case, since may your TP has varied little. Thatâs usually a good sign.
Thanks @xertedbrain. Ultimately, I went the ill-advised route instead and hit recalc signature after flagging a few activities and making sure all of the last 3 years were imported
Activities I flagged were ones such as when a mate attacks on the group ride and you jump to stay with but then coast rather than push that effort to failure or a race sprint where you stop because you crossed the line. Is this the correct idea for flagging along with bad data like drop-outs? Iâve never really bothered to flag before.
Signature looks much better. HIE seems a touch high still based on failing 3/5 intervals in second set of Kung Fu Fighting even on old signature & now the 3 MMP is higher but hoping thatâs more about AUTO mode vs needing to hit them in Slope.
One weird anomaly, in progression chart, there is a huge TP jump but no BT bubble. The activity on that date itself is flagged as a BT.
Ooopf, long time no proper BT or even a good fully committed attempt. Pretty scared to go into the next workouts with this. Probably going to tune down the sessions a bit.
Big breakthrough! Congrats!!
When was your last Breakthrough? What has your training load done in that time?
Aaand thatâs my plan done for. Now back in the mud where XFAI just straight up refuses to build a plan for me.
Guess Iâll have to manually lower my power profile to get by the Forecast AI Police.
Lord alive this is frustrating! Punished for getting fitter .
I had silver (TL 32) on Dec 5 and bronze (TL 35) on Dec 22. Now the TL is at 63. So a big leap there as well.
Mostly done base stuff, but consistency is the key as always. One thing to take in to consideration is how well the ramp test protocol suits my power profile. It often leads to a too high FTP estimation.
Looks pretty good to me. 
You can view details of your BT by viewing activity details and select the Previous button under the chart. That will show you where you exceeded MPA, for how long, and how many times.
The Current button returns you to the adjusted chart with your new signature applied.
You donât want to mix running power data in your cycling profile or youâll get invalid results like the BT you generated.
After months of mostly indoors on my XFAI plan along comes a warm spring-like day, a few short hills, the wind behind your back on the return, plus a final hill sprint, and this will happen.
