This episode has Mork exercising with Mindy.
Mork ask Mindy what is the name of the exercise they are doing.
Mindy tells Mork that it is called The Bicycle.
Mindy then asks Mork why he stopped moving his legs.
Mork tell Mindy he doing the exercise called The Moped.

The episode was "Hold That Mork" in Season 2. It wasn't Mindy who was answering him, it was one of the Denver Bronco Cheerleaders who where teaching him the cheers so he could try out!!