Historical Peak Power Numbers Keep Changing?

On Sunday, my PP was 1080. This is actually documented in my weekly training stats. I’m looking at my Fitness Signature line this morning and noticing that Sunday’s 1080 has turned into 1064. Why is that? Thanks for any help on this.

Hi Erik, did you upload any activities with power or add any manual activities to your progression that occurred before Sunday? Also, what is your decay setting?

Thanks for trying to help me. If I understand the question correctly, I use a power meter for all of my cycling activities. All activities have come from Strava to Xert. No manual activities have been included. The decay setting is on the default - “Optimal Decay”.

With optimal decay selected, your PP numbers are tracking with changes in your peak training load. It shouldn’t be a problem, as most of the changes are within a relatively small range.

I guess that’s my question - why wouldn’t your historically data hold. I can understand that my PP and/or FTP changes with each day (in the present). However, it doesn’t seem like my historically data shouldn’t change - It’s done.

All depends on decay method in the system since feedback (breakthroughs) is the best way to know. No Decay reduces the occurrence of breakthroughs.