Garmin vs. SUF: who do you trust?

I have a Garmin Fenix 6 which is connected to the same trainer as SUF. However, I get drastically different miles ridden and miles per hour from the two sources. SUF tends to be about 30% more than Garmin.

Who do you trust?

TIA, Scott

Not trying to be cheeky (promise) but neither is right because you are suffering on a stationary device. Speed is not really comparable across platforms and certainly not compared to the road. I see mates on Zwift on endurance rides averaging 35+ kph and there’s no way they could do that outside!

So your miles ridden and mph are really only useful for comparing to other SUF workouts. Other metrics, like ride time, HR, kj, and watts are much more valid and comparable across platforms, IMO. Others may have more valid opinions!

Edit: typo


Hi Scott,

This is what the Sufferfest has to say about miles ridden on a trainer:

Maybe a nice insight in their reasoning to display/not to display speed and distance on a trainer.