FTP increase not detected

I did a race yesterday with a best 20 m power of 263 w. My previous FTP was at 235 but zwift did not recalculate my FTP at the end of the race. Why is that? Is it only 0.95 x the 20M power that is calculated or is the algorithm also looking at power surges and variability in power when estimating if a new FTP threshold is reached?

Soren,

This is what Zwift Insider has to say about the subject.

Zwift automatically tests your FTP on every ride, prompting you if an increase is detected. Your FTP value is calculated at the end of your ride as 95% of your highest 20-minute average power.

Example: if your FTP is set to 270 watts, and you averaged 307 watts for 20 minutes in a Zwift race, the game would prompt you with the screen below when you finished your ride:

Yes thats also what i have seen. But 95% of 263 is 250 watt and that is higher than 235 so why dont i automatically get the FTP increase calculated in the zwift app?

Soren,

I think sometimes Zwift misses FTP increases due to various reasons. I have changed mine manually when an FTP increase is due. If you are on Zwift Power you can see what is there under Minimum Category → Info. It shows your three highest W/kg in events that are logged to Zwift Power.

I am on ZP and the race is logged correctly there …and that’s the most important in order to log progress towards new category. Glad to hear that Zwift sometimes misses the increases.

you can manually update your FTP on both your Zwift profile and your ZwiftPower profile, if it bothers you that much.

&
Zwiftpower → Profile Page → click Settings