My TP is always 25%+ above my actual FTP, starting from my first activity uploaded and including breakthroughs. I have a fairly low training volume, low endurance, and strong < 5 minute power. Even if I manually correct TP down and HIE up on past rides, new rides with anaerobic efforts show breakthroughs to inaccurately high TP.
Here’s an example ride. In this 25 minute crit, I set an all-time 20 minute power PR of 282 watts, but the Xert fitness signature for this ride shows 350 watts at 20 minutes, 29% higher than my actual 20 minute max effort. Xert calculates a breakthrough TP of 312W for that ride. My actual TP is around 250W. Is there a fix for this? Thank you!
Maybe you can share your full fitness signature as well?
It could very well be that your PP and HIE is too low, and your TP too high. A good start can be to actually test your PP (push as hard as you can for five seconds or so).
How much history have you uploaded into Xert?
Is it a mix of indoor and outdoor rides?
What is your current status stars count?
What test method was used to derive your FTP value?
My best real-world 5 second power in the last few months is 1068 watts. I recently did 850 watts for 30 seconds. My lifetime PR for 1 hour is 233 watts
I think that’s unusually skewed to anaerobic power. Is that what’s confusing the algorithm. Is there a fix?
Here’s the fitness signature for the same ride. It includes a maximal 20 minute effort (with high VI, which skews more to my strengths than steady state), and the 760 watts or so I did for a few seconds was a 100% effort at that stage.
3 months of data uploaded. The inflated TP starts with the very first ride uploaded…a super easy social ride. I requested a Garmin sync for the previous year, but those numbers are going to skew even more to anaerobic power.
It’s a mix of Outdoor rides and Indoor rides on rollers. All of the breakthroughs are from sprint efforts in outdoor rides, even if the avg power for the ride is 130w.
Current Status: 1 star. I’ve spent about 50 hours on the bike in 2024. Hoping to use Xert to start a training block.
Test method: All other platforms estimate my FTP at around 260w based on my maximal 20 minute effort in the ride I posted. I tested at 255W on a ramp test a month ago. Even those are probably slightly high. My actual 1 hour threshold is probably a little lower.
Here’s my power profile from another app, feels pretty accurate:
That ride was not a steady state effort so just taking a % of avg power is not a good estimate of FTP. What was normalized power?
It’s probably worth re-testing with a long steady effort… 30 to 40 minutes… better to start low and increase every 10 min than go out too hard…
If you can’t get near the Xert TP then the suggestions to fix it from other posts are valid… especially re peak power… are those recent ‘bests’ reflective of your max efforts, or just what you’ve observed in normal riding? You need a max sprint effort (ideally outdoors as it’s hard to sprint indoors)… go out and do that next time you are fresh and warmed up…
Not sure anyone said anything about 80w… anyway, I just meant the suggestion that PP and HIE are too low, which is also why asked if those are max sprint and 5 min efforts. You can also manually increase HIE (given you confirmed PP is broadly correct) and re-extract a signature from that BT effort, but ideally you shouldn’t need to… just go into the activity, lower TP to eg 270, increase HIE by a few points, click extract, then save / lock assuming you like the result
More broadly, there are some users that feel they have inflated signatures when doing repeated on-off efforts (like your crit, or Ronnestad workouts) - there are potential reasons given e.g. power meter errors / sticky power, but that doesn’t really solve it. if that’s the case the only other option is to flag those rides, and make sure you only get BT efforts from steadier efforts I guess - which i agree is not ideal
You can contact support@xertonline.com and ask them to take a look at your data and adjust your starting values. Xert Support can best advise you on what’s triggering the difference.
If’ you’d like more feedback from the community, post your XPMC chart set to 3 months or YTD.
That will give us a better idea where you’re at and perhaps explain the gap between values.
