So, I should flag any breakthrough that was unintentional and didnât involve going to failure, correct?
Yep, the system is based on the assumption that you are toast at the end of the effort
Ok, but you canât really be completely toast after just a ten-second all-out effort. Does that mean I always have to follow up a sprint all-out with a significant amount of time spent above TP, until Iâm fully exhausted, to avoid risking inaccurate fitness signatures that Iâll have to flag later?
@Craigol @ConorP I do want to emphasize that you donât need to do constant power efforts to failure to achieve Breakthroughs! Traditional platforms rely on this because they estimate your FTP from some percentage of 5 min, 8 min, 20 min average power⊠Xert doesnât use average power at all, but rather looks at how your MPA limits your ability to produce power when youâre under fatigue 
This allows Xert to detect changes in your signature from highly stochastic & variable power data, such as that from a race, hard group ride, etc. Hereâs just one of many examples where the athletes avg 5 min/20 min power might be relatively low (compared to if this same athlete were to do a max 20 min effort), yet Xert still detects this ride a maximal/breakthrough effort:
Yes, but there are counterexamples â those incorrect breakthroughs. In the example above, my new TP was supposedly 249 (previously 212), caused solely by a single 10-second sprint at 1200 W. But after I flagged every breakthrough that didnât involve going to failure and then did a new one â this time actually going to failure â my new signature is only this:
Thatâs quite a big difference from the previous one, which was clearly wrong (the LTP felt way too high during riding):
So, is it fair to say that âyou donât have to go to failure with Xert for a proper FTP/signatureâ is more of an ideal â but not always the reality?
I didnât mean to imply you have to flag activities like that.
I would if the jump pushed HIT workouts beyond my reach or o/u LTP intervals felt off.
You have the option to flag activities whenever you donât feel the change is warranted.
You also have the option to edit a signature change or manually adjust your signature.
If youâre unsure about doing that on your own, you can file a support request (support@xertonline.com) and Xert support will take a look at your account settings and history.
Once familiar with how the system works you can experiment on your own which is what many of us longtime users are comfortable doing, tweaking things along the way.
The algorithm isnât infallible. 
Neither are RAMP or 20-minute tests.
Since that BT boosted TP/LTP substantially I assumed that was too much of a change for you at that time. However, I donât know your training load history and what youâre capable of.
The point is you donât have to accept every BT. When you flag one you can continue to train at your prior values and prove if a change was warranted by your future efforts.
Homing in on your signature is a combination of TL intensities over time including occasional points of failure to validate where youâre at.
1 Like
Nothing crazy here, just looked down, saw i had 30 seconds to a breakthrough, and through, ah⊠why not give-er
2 Likes
Correct. Itâs hard, very hard to extrapolate oneâs threshold power from a relatively short sprint effort. Xert also captures what we call Maximal Effort Time, which is how much time you spend very near your MPA. From the glossary post: âGenerally speaking, the greater the Maximal Effort Time, the greater the expression of the athleteâs fitness occurred in the activityâ For example, a single 10s sprint might not be the best expression of your fitness compared to a hard group ride with many consecutive efforts that push you very close to your limits over the course of many minutes. The latter would be a far better expression of an athleteâs fitness.
In case you didnât know⊠the size of your breakthrough circles in the XPMC chart correspond to the Max Effort time of that Breakthrough/Near Breakthrough activity. The larger the circle, the deeper you had to go to get that breakthrough (or near-breakthrough) effort. Meanwhile the little âcheekyâ breakthroughs where you sprint for a few seconds are seen as relatively smaller blips. Hereâs an example from my XPMC:
Did this using Rouvyâs new slope mode. Easier to select a gear and hold a steady wattage. Replaced my Elite turbo trainer for a Wahoo Kickr core with the Zwift Cog and Click (itâs excellent on Rouvy).
I think my signature is a little off but I feel with a new trainer a few more breakthrough might be needed.
1 Like
I did the Xert Fitness Test for Breakthrough â Version 2 to get an accurate signature. Looks like I got it.
The previous graph:
5 Likes
Great job Simon! 
Were you monitoring your MPA during your ride? Or were you just feeling good/pushing hard and it was a surprise Breakthrough once you uploaded the ride?
Ahh - I missed this update from Rouvy. I wonder if Xertâs Mixed Mode workouts will be supported by Rouvy now. Iâll have to do some testing when I get a chance!
Congrats on the Breakthrough!
1 Like
Thanks, I had the Xert dashboard up on my Garmin, but wasnât really paying attention to it at the time, just focused on trying to get the top of hill. I did spot the breakthrough icon once I had time to relax and look at the dashboard.
I find it a bit hard to see how far I am from a breakthrough (in XMB) (when getting close to it). Maybe this could be improved somehow? Especially outdoors when you might be out of the sadle and the light be changing a bit due to shadows from trees or buildings. Maybe I am just getting old 
Maybe the problem is that XMB doesnât show MPA so you have to rely on the visual to see how far the current power is from the MPA.
1 Like
Well that was a total surprise. I was not using XMB so wasnât watching the Garmin screen. I managed a gold BT without trying !!
Just an easy Rouvy challenge ride and I pushed a bit at the end to catch another rider. The summary told me I had my best 1 minute power in the last month but I thought nothing more of it. Then looking at Xert I saw the BT. By the narrowest of margins on all 3 parameters. 1.5w, 0.2kj, 0.7w.
I would be surprised if there were many gold breakthroughs with more insignificant numbers than mine.
1 Like
Actually had three break throughs on this ride. a slow draw down up a long hill, then a short respite and attacked again, followed by an all out sprint. So pleased with that as I wasnât really feeling it at the start of the ride
3 Likes
