Zwift zones

I’m new to Zwift but not new to FTP or zone training. Yesterday after completing a 1:50 session, my swift analytics informed me I had been in zone 5 the entire time. This can’t be possible.
Clearly, my zones must be calculated incorrectly. How do I fix this?

You can set it yourself if you know what it is, or you can do an FTP Test to have a better estimate. Zwift will also auto-detect FTP on your rides, but if you don’t do a maximal 20min effort that estimate will be off. Zwift also now has zFTP on your profile on zwift.com, so if you do one maximal effort which is in the 5min range and one in the 12-15min range that will also give you an estimate.

Are you talking about Power zones or Heart Rate zones ?

Looking at your yesterdays 1hr 50 min session (a race) you ran the whole race in zone 5 heart rate, impressive if correct.

Looking at a previous workout your zone 3 was around 135watts and you only did this or more for 10 minutes in your race. Seems unlikely that all of your race was in zone 5 power.

A few questions which might point towards help and advice. If you have experience of FTP:

What do you think your FTP should be?

Did you feel that you were almost at your max effort/hr for the whole race?

Do you have any outside distance/time performances which might suggest a normal cycling power?

Edit:
You can also press the G key on your keyboard (assuming you have one) to see your power graph at bottom of the screen.

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You can also see an analysis at end of each ride by choosing/looking at your end of ride timeline report:

https://support.zwift.com/en_us/your-ride-report-HJ8dAVer