Can anyone say why this isn't a BT?

I ran a solo 5000m time trial on a track today, averaging a solid 4W higher than my PDC says I could do for a duration ~2 minutes shorter than the time trial lasted. Can anyone shed some light on this for me?

Xert Time Trial

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@amcnabb Try it now!

Sustained efforts that start and end like that are not a good match for Xert’s signature algorithm.
See: Breaking Through the Xert Way! – Xert (
There are similar posts regarding this scenario but my guess is you’re an endurance athlete who probably never sprints and possibly can’t sprint.
If that’s the case you might consider a standard RAMP test to estimate FTP although FTP is not the same as TP in Xert.
There is a RAMP test in the workout library: Xert - Workout Designer (

Yes should be a BT but sometimes the algorithm can misinterpret such steady efforts with a sudden stop… as noted by @ridgerider2… I also have some old style FTP tests in my history that had a lot of time above MPA but didn’t trigger a BT. It was long enough ago that I don’t care though.

Don’t know the technical reasons for it, but you can manually adjust your signature for this effort. Go into advanced MPA, then increase TP (and maybe HIE a bit?) below the chart, and click refresh. With some trial and error you’ll find some numbers that lead to MPA just touching you actual power at the end. Then click save.

Alternatively contact support and am sure they can do it for you, and probably better explain why a BT wasn’t triggered while they’re at it!

A ramp test for a runner? How does that work :wink:

Thanks for the suggestion! I did that and quickly got a signature that looks more reasonable.
It has been a while since I’ve done an activity like this, and had forgotten about TP undershooting some with a sudden activity stop like this. Next time perhaps I’ll just hit “lap” to mark the end of the trial and try to keep going however long I can before failing completely.

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