I have never trained with a power meter have no idea. I just got a Tacx Flux 2 so i can now do a FPT 20 minute test or a ramp test that is shorter. In some way I don't want to kill myself so going give this a try since doing it outside without a power meter is impossible. It seems the full 20 minute test actually takes about an 1 hour to complete but the ramp test you just go till you can't pedal anymore.

Anyone try either and get same results or close, and then possible compared to outside. I am asking us older folks here because in some ways it makes no difference to me what it actually is but could be a guide.