Discrepancy on my FTP test result

Last Friday I’ve completed the 4 wks FTP Boost workout and I did the FTP test.
While running the test a pop up was indicating the FTP avg I was achieving and almost at the end the pop up was around 335, Just after finishing the test the final pop up was stating, w/ my surprise, that the new FTP value was 222W.

Someone could you explain to me why the final value was more that 10W less then the indicated avg.

BTW on Strava I saw the workout analisys and the average power recorded during the test section was avg 235W.


Remember the test is 20 mins and FTP is for one hour. So your estimated FTP will be less than your 20 minute average. Maybe that is the reason?

Just to be clear, was the “335” a typo and was that your “FTP” average or your “power” average?

If it was an FTP of 335, there really is a big difference! And you are a very fit and strong guy!

Assuming the 335 was a typo and it should have read 235 then it all make sense.

FTP = 20 power x 0.95
FTP = 235 x 0.95 = 223w

So it look like Zwift did the correct calculation.

Yes I’d forgotten the 95% calculation. Unfortunately the misure value was 235 and not 335 :grin:.


1 Like