Peak power did not update

Hi all.

This morning I did 2 maximal sprints during a recovery ride because I felt really fresh and was sure I could improve the peak power from my fitness signature. These 2 sprints were both 8-10s long with an average power of around 800 and a peak power of 1098 and 1115, however, my peak power in Xert is still showing as 985w. Why is this and how can I let Xert do a recalculation so it is updated with the correct values?

I tried manually filling in the 1115w value for the activity but I get a message saying “The system was unable to extract fitness signature” .

Thanks in advance for your help.

See this thread – Is PP a theoretical number? - General - Xert Community Forum (

For my activity it seems it is only seeing my sprints as a power spike which does not accurately reflect my fitness. I think on a very good day when fully rested I could even achieve higher than this so I’d like to update the fitness signature to reflect this effort from today. Would I only need to update the peak power or also the high intensity energy in this case?

If you consistently prove higher numbers especially during BT events (under fatigue), PP will rise accordingly. Otherwise, the signature algorithm is working as designed.
A spike while fresh won’t likely update the number especially if within expected range.

On a fully rested day you should consider a BT workout or similar activity outdoors where you draw down MPA first then sprint for at least 5-7 seconds (until failure). The algorithm will calculate your theoretical maxP based on what you can muster while fatigued.
Your PP is never actually an exact number but rather an indicator of what range power you can achieve.
Also consider power meter accuracy. Even if your power meter is 1% accurate 100% of the time, 1000 watts would be in the 990-1010 range.

The goal is to settle into a valid range of values based on your data then monitor your fitness signature changes over time.

Reference –
Breaking Through the Xert Way! – Xert (
Your Fitness Signature – Xert (

1 Like

I don’t really understand your answer. I think Xert does not have enough data imported because I only have been using it for 2 weeks. I really feel like the 985w that Xert is giving as PP is way too low, even as an all out effort at the end of a race for example. I have been riding for 5+ years with a power meter and know what sprint power I can do normally and I would like to update the number in Xert. How can I do that, and do I need to update the HIE as well in that case?

Note #3 here explains why extraction failed with the recovery ride –

You can seed your account by syncing more historical data that includes maximal efforts that indicate BTs (circles on your progression chart), or generate a current BT, or enter known power curve values here – Xert - Power Duration (

You can also manually adjust signature values by viewing your most recent BT effort workout/activity as linked under your name on home page of XO. You can make changes and save them there.

Lots of newbie tips in this thread if you haven’t already seen it –
Beginner questions - Support - Xert Community Forum (

Complete Academy series videos –

You should upload your past data as well - no need to only include new data (unless the old has lots of errors I guess)