Training plans - FTP and cadence


Fairly new to zwift so still getting to grips with some of the nuances of the gear so apologies in advance for any misunderstandings.

I’ve signed up for the gravel destroyer training plan, but am having a bit of difficulty with managing the efforts because it’s asking me to maintain 75, 90 and 100% of my ftp while staying at 65rpm cadence.
To maintain those ftp levels, my rpm needs to be between 70 and 90.

I assume that this is because I’m using a ‘dumb’ trainer with just hr, speed and cadence sensors attached to the bike. It’s set up as per the manf. guidance and the resistance setting is correct. I thought of increasing the resistance to slow my cadence down, but then I assume that the ftp will read incorrectly.

Is there a way to tell zwift that I’m upping the resistance, or will i just have to accept that these are the limitations of my setup?

Even if you have a smart trainer you will not be penalized for not being able to meet cadence goals (although it will definitely help to). Sound like you are limited with the technology you have so as long as your trainer is set up properly you can only work with what you’ve got.

Thanks, I’ll just concentrate on the power and work with the cadence where possible then.