TL-DR > re-syncing to Zwift the prescribed workout after a FTP change would be neat
Long form :
First, just to be sure it seems that TrainerRoad sessions sent to Zwift is not based on Zwift set FTP but the file push to Zwift is Watt based. This means that we don’t have tp update FTP in Zwift. Is it right ?
Based on this, I noticed yesterday, that following a new FTP detection trainings already pushed to Zwift are not updated for the new FTP. I tried change the FTP in Zwift, but the session watts was not impacted.
I had to change my session to another, then back to the original one prescribed by tha AI in order to have it sync properly with Zwift.
You are correct that the FTP set in Zwift is irrelevant to the TR workout sent to Zwift. The workouts sent from TR to Zwift are based on your TR FTP and sent to Zwift as fixed watt values. What would be different in Zwift is that it might show your power zone summary incorrectly, especially if there is a large difference between your TR and Zwift FTP values.
As for the workouts that have already been pushed to Zwift not being impacted by an FTP update in TR, are you positive about this? I would have thought that TR would automatically update the workout in Zwift after a TR FTP update, but I can definitely see it as a possibility that it would not (which, then, would seem to be a bug that needs to be squashed).
it will be a few more weeks before I have another FTP update to check this, but maybe someone else has one coming up sooner and could check. Whatever the case, though, I suppose it would work itself out after a few days, since workouts aren’t pushed to Zwift too far in advance.
My FTP detection was on Sunday and the Monday workout was already synced prior to that. So, for my case, I certainly it did not triggered a resync when FTP changed. But maybe it was a just a hiccup but I can only reconfirm in 26 days.
if others can check too, maybe it will ending being a bug to be squashed
I had a training plan loaded into Zwift and when my FTP changed yesterday the rides for the rest of the week did NOT automatically update to the new FTP
One work around I found was to go into Zwift and select the old workout (with old FTP) and hip the copy button. Then at the bottom you can change watts to %FTP and for me it changed the wattage to reflect the new FTP.
it seems as if the new FTP is still somehow communicated to Zwift but not reflected in the wattage for workouts loaded prior to the FTP change. Would be interesting to hear from the TR team about this