I read about this yesterday, and my immediate thought was, "it's a Fry & Laurie" sketch come true!"
And I went on to Youtube to look up "Dancercise" (the actual Fry & Laurie" sketch) only to find loads and oodles of videos about Dancercising that had nothing to do with Fry and Laurie!!!
You just couldn't make it up.
Anyway, have some Fry & Laurie. The original actual dancercising.