Celebrity Workout Videos You Never Knew Existed [VIDEO]

Like every self-respecting Gen-X'er on the planet, I knew the words to Olivia Newton John's "Physical" forward and backward. I also watched my mom struggle through any Jane Fonda workout video ever made.

But did you know Jane wasn't the only celeb with a hand in the video-cising craze of the 80s???

Alyssa Milano's 'Tenn Steam'....Estelle Getty in 'Young at Heart'....and this classic Cher tape, aptly titled 'Cher Fitness'....