It al depends what gear you are using ! if done in the smallest ring in the front and largest in the back your average speed will be much lower than when you use the big ring in the front and the small one in the back ! it is watts that count when training indoor not your speed !!!
Forgot to mention that your Cadence obviously influences speed as well but just ignore speed when training indoors .
Speed and distance are irrelevant when using a trainer indoors. It is even more true when using ERG mode on a smart controlled trainer.
The real issue hiding under the speed umbrella is flywheel inertia. That is a very different discussion.
The speed is not real and is not taken into account by TrainerRoad, the results are valid
Thanks. I was on the big ring and 11 in the rear.