Questions about signatures, and manual correction

I’m still trying to get an understanding of how this signature is computed, specifically the methods used for correcting it, like the MPA setting, etc. So let me ask the question this way. It’s my understanding, and please correct me if I am incorrect, that Xert will tend to correct itself, or put another way, home in on my correct power curve and signature. On the other hand, I have seen references here and in the facebook group that suggest that sometimes the situation is beyond Xert’s ability to correct, and one needs some sort of manual correction, either through the Xert interface, or if really bad, through the intervention of Xert support people. So my question is, 1) how do you know that your signature is wonky, 2) in what ways can it be wonky, in which aspects, and 3) what are the various ways of correcting it manually? To give you a couple of examples, in one workout my TP increased 10 points. That seemed unrealistic to me. I thought it might be because of less-than-maximum PP effort, so I reperformed it, and increased my PP by over 100w. I followed advice here, opened the activity, clicked MPA, manually added the new PP, and clicked save. I believe the new data was then incorporated into my signature, as I had an instant breakthrough, PP increased the 100+w. There was no change in the other parameters. Did I “fix” things? Why is my TP still the same? Is that Xert’s way of telling me that I indeed had a real 10w increase previously in TP, or should I have followed additional procedures (or a different procedure?) Another possible issue is that my LTP seems high. My TP is about 16 % higher than my LTP. My LTP is 30w higher than my LT1. I estimate my LT1 by noticing how my breathing starts to pick up during a workout. So…Is my LTP wonky, and why, and how do I fix it? As far as my increase of 10w in TP in one breakthrough, I guess it’s possible, as I hadn’t been working out much, and perhaps my blood volume increased very quickly in the few days preceding that workout, (blood volume can quickly decrease after a layoff of as little as a week, but it comes back quickly) but I still think the 10w increase is unlikely. Maybe I’m wrong. Here’s the bottom line. I want to be sure my signature is correct, so going forward, I can make an appraisal of how Xert can be a useful tool in my training. Right now, i feel like I’m flailing a bit (a lot!) in my understanding of what’s going on. Thanks…

Xert recalculates your signature after every activity and makes adjustments anytime a breakthrough event occurs. Your signature can also decline from lack of activity and BT events.
So yes, Xert tends to correct your fitness signature over time. :slight_smile:

A 10w change is not unusual especially as your fitness improves through the phases and your training load increases.
Examples: Let’s See Some Recent BT’s - General - Xert Community Forum (

If you use the Advanced MPA tab to change PP for an activity you want to click Extract first to see what the new signature will be then click Save to use that change moving forward.

One simple way to validate your signature is compare your HIE to PP in this chart –

Are there errors in my Fitness Signature? – Xert (

Breaking Through the Xert Way! – Xert (