Riding in which gear and chainring?

Is there a certain chainring and gear I should use?

I completed The Gorby and trying to get the 315w power I had to move to the very lowest gear and the small chainring. At one stage it was almost impossible to turn the pedals over.

Then I noticed if I peddled a little faster it become a tad easier.

The next hard part of this workout I left the big chainring on and a higher gear. Impossible couldn’t move.

On the third hard burst, I was able to leave it in the bigger chainring and still achieve 315w.

On the 5 min rests, big chainring or small chainring, was able to achieve 160w.

Does this sound normal?

Mate we need more info to help you, what is your trainer? is it smart, are you using just a dumb trainer with zpower? is it a dumb trainer coupled with a power meter?