I bought these several years ago for probably $30 or $40. They're giving it away right now for free, so I thought I'd share the link. We've done some of the lessons, and I'd give the program mixed reviews, but you can't complain too much about FREE!
The lessons can all be done indoors, so if it's still winter where you are and you'd like to get your kids moving, these are what you need.
http://www.familytimefitness.com/fitness4homeschool/Fitness4HomeSchool.phpOffer lasts until the 21st.