Could be⊠or could be that itâd been a long time since your last breakthrough, and your signature had decayed significantly? you can see on your progression chart.
Either way, if it wasnât an âall-outâ effort, your signature is probably still too low⊠time for another breakthrough 
I had another BT last night!
Xert was telling me it was past 3 weeks since my last BT so I did some really hard wingers on a group ride to pull my MPA down. It was a good ride, im still impressed with how well the system reads me.
did a race a moment ago, leg felt good for the 1st few km into the race, so, decided to go for a breakthrough to reset fitness signature which due for 1 month.
Not really chasing BTs just trying to get ready for Zwift racing in September and be competative. Built a lot of base Jan-April then introduce Sweetspot and Tempo before using continuous improvement from June before deciding to use TED. Since June Iâve been trying to follow XATA as best as possible but subbing out some intervals for longer easy LTP and below rides that suit my schedule and give me a bit of respite. Feeling stronger than ever. This quick zwift race - first time with A group gave me 2w and was chuffed as it wasnât intentional. Now at 287w from 272w at the start of June, confident I will see 300w and incidentally already at my highest TP ever
Different Kind of Breakthrough ⊠after my 3-week touring (5000k) trip my LTP is now claimed to be above my starting TP! Another example that Xert-Fomula simply canât handle long distance riding hrm donât know why I stick around to it.
For all practical purpose I barley managed 170 avg (show by my bolt only counting active pedal time) on the last days and even less on the days before.
Also final Training Surplus: 1411
I was doing some 7 x 3 min @ 105-109% outside, and after the intervals I pushed hard for some time and realized that my MPA was drained, but I still felt quite okay. I therefore tried to drain it further to go for a breakthrough, which I successfully did.
Btw, it would be nice if it was possible see how far below the MPA one has been able to go on the Garmin data field. Now you only see the gold/silver medal, but you do not know if it makes sense to push further or if it is okay to let it go.
I am truly humbled by this⊠BUT I am wondering if the powermeter is that far off from my road bike one. They are both Favero but the MTB one is single sided and the road bike one is dual. I compensated the MTB unit for my leg differences but still has me wondering.
I know my TP had drop drastically before this race as I did not attempt or have any breakthroughs for a long time, so that increase is amplified but still.
That said, I FELT FANTASTIC AT THIS RACE. This was my late season A race and I think I hit the nail on the head and looking at my HR data I never went into any distress. I ended 2nd place and felt like I had so much power on tap.
Congrats!
In a case like this where you have the breakthrough for only a few seconds, how will Xert know if TP or HIE should be increased?
Iâm not sure, I leave it up to the program to figure out. In the past the TP on Xert has been reasonably close (within 10 watts) to other test methods. Overall I trust it but this is first time Iâve had an FTP of 268.
The classic answer⊠it depends!
In general, Xert will determine which parameter(s) need to change based on the interaction of MPA & Power when the BT is achieved. Generally speaking, the longer MPA & Power are close/interact with one another, the more certain you can be that the resulting fitness signature is accurate. We also have general ideas of where we expect your HIE to be, given your peak power, which helps improve the certainty that the signature is appropriate.
I never had a gold Breakthrough.
I used to feel like Xert wasnât âdialledâ to me and I assumed I wouldnât be able to get above a silver one. But last week, with my new KKM2, I felt confident and I gave it all. I had my first Gold Breakthough and it was at THIS moment I understood what it really takes to get one : I had never truly had the courage to bit the frea-king bullet and leaving nothing on the table. It made me scream out of pain. But man I was proud.
Fast forward to yesterday, I felt so good yesterday from a 2h ride. So I decided to just go for a short ride, again, in the pursue of this precious metal.
GOT ANOTHER ONE.
Well, Mesdames et Messieurs, Iâm hooked.
(As a note, I gain 40W of TP, but this is an obvious bounce back from my PB from this winter, but hey! Now my Xert Fitness signature will be more on track with my actual fitness signature, so I can TRULY suffer, hehe)
Nice work! I donât think thereâs really a thing as a âbadâ Breakthrough In your case, your HIE was a tad bit higher than Xert would have predicted after a week off! 
Got my first breakthrough today since actually signing up for Xert!
Seems I just need to the carrot of a race to make it happen!
Am curious why my profile is quoting PP +14W and HIE +0.3kJ above the breakthrough numbers immediately afterward if anyone knows? Only small diff though.
Congrats on the Breakthrough!
We call this the âdouble dipâ effectâŠ
Itâs been a while since testing a longer effort as Iâve focused on the shorter efforts. After a short lay off and changing my decay rate from no decay to optimal decay my TP nosedived. Took part in a Zwift race which included a 6.5min KOM segment for points (6th of 55), and a Sprint segment for points (which I took outright). Finished the race in 9th place in time but joint 1st in points. And a massive breakthrough to boot. That should be the fitness signature back on track now.
