Azarizotza got it right in the comments for “The Horror.”
I remember watching this early in the morning when I was 5 or so. I think I just watched, mesmerized….but never actually went a long with the exercises. Ahem, I mean, mousercises.

↓ Transcript
Close up of Chloe pulling on a leg warmer.
Close up of Chloe putting on....mouse ears?
Chloe (wearing a pink leotard and leg warmers and black Disney mouse ears, standing before mice): Let's do this!
Chloe and the mice do aerobics in front of a youtube video of the old Disney show, Mousercise.
Kellyn (from the youtube video): It's Mousercise time, boys and girls!