You can learn something from TV! Great leg workout!

So I learned this exercise from watching this commerical with J.R. Celski (US speed skater); I did a leg workout tonight at the gym which is why I mention it. The exercise where he's doing the one-legged squats on the ballon pad thing. It is VERY hard to do even on a flat surface. I do three sets of 7-8, and my legs are a little sore the next day; and that's on a flat surface at a faster pace. Doing it on the ballon pad thing makes it 10x harder; it really really challenges your balance and works all the smaller muscles. Doing it slow like J.R. makes it another 2X harder. You have to have a lot of strengh and balance to do it slow like that!