Strength Workouts - Fail

Hi all -

I’m entirely new to Zwift and am working through the FTP Beginner series of workouts. I am using a Kinetic Rock and Roll and have made sure all firmware is up to date and the trainer has been calibrated. I’m trying to figure out what I’m doing wrong that the 10 second resistance sprints don’t offer any change in resistance … until about 20-40 seconds after the sprint is done, at which point the trainer suddenly kicks up the resistance during the rest period. Erg mode is on, so I would expect Zwift to tell the trainer what it should be doing.

I have tried changing gears to meet the wattage requirements, but can’t get that changed fast enough to get up to where I’m supposed to be for 10 seconds.

Any tips?


Depends on the trainer. I have a tacx neo 2. The power kicks on at about 5 seconds into the interval. And off at about 5 seconds after. I’ve gotten used to it by now. So start spinning up the cadence when the interval starts. And can cheat the last 5 seconds by going with the momentum after the interval ends :grinning:

I’ve been having this same issue for months now. I’m on a Kickr Core. I have been unable to do any workouts (group or singular) because the intervals are 30 seconds behind and by the end it’s minutes behind. After back and forth with Zwift, they just said to wait for an update. It’s really upsetting. My only options are ride alone or group rides. I like them, but I’d really like to do workout but it’s impossible. I hope it is fixed soon.

Hi @Danielle_Sowle, welcome to the forums. I also use a Kickr Core, but don’t have the same issue you are experiencing. What device and connection do you use for Zwift. I am on a windows 10 PC with an ANT+ dongle on an extension cable right under the trainer. This works flawlessly in ERG mode for workouts.

Have you also updated the Kickr’s firmware and do regular spindowns?

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Hi Mike! Thanks for the response! Wahoo is paired via Bluetooth to my Windows 10 laptop. Firmware is up to date, I unpaired and repaired and all that jazz while with wahoo and zwift support. I also have a cadence and HR monitor via Bluetooth. I have unpaired each and tested a short interval workout, but the problem persists. I have only been able to do group rides without issues. So I warm up the kickr 10 mins prior, perform a spin down and then join the rides. I currently have an ANT USB receiver In my Amazon cart- that was my next step. Im hoping I can pair the kickr via ANT and the rest Bluetooth. We will see…

Do you have an old Kickr that can’t estimate cadence? You might be able to pair all of them with ant+ and skip bluetooth all together. I think you will find that ant+ is a much more stable connection.

Hello! I just got my ANT usb receiver and tested a workout with short intervals and it wasn’t lagging!!! Next test is group workout since that’s when I first noticed. After months with zwift support, im happy to found a fix. I wish they would suggest that earlier, I had to do my own research. Thanks again!