Looking for a bit of advice here - did an FTP test this evening with my new Precision 4iiii left sided power meter and a Tacx Vortex smart trainer. I had the power reading on Zwift from the trainer and the power meter reading through my Garmin.
Have noticed since getting the power meter that on hard efforts outside the power was sitting a lot lower (270-290 watts) for 20 minute efforts compared to what I have been doing on zwift recovering from injury over the last few months (could easily hold 320-330 for 20 minutes).
Did 20 minute FTP test today with average power for the twenty minutes on zwift of 375 and on my power meter of 285!!! My previous FTP in October when last checked was 314 on Zwift.
Does anyone have any tips for what to do here - I checked my trainer calibration on the Tacx app at the end of the ride and it was in the green zone. Is Zwift just massively over estimating my power??