To give you a little fitness for your classroom, since you probably won't be able to get away with the HP Workout plan on rainy days, here is a website that I use with my kids when we can't go outside for recess: Adventure to Fitness. I really love it and the kids are too funny when following along with the guide Mr. Marc. He takes you on an interactive/physical mission to capture an evil mastermind, all the while your kids are working out and learning about new civilizations, events in history, etc. I really like it for multiple reasons but it gets the kids (and me) up and moving and learning and it's free! Just sign up using your email account and viola!
I promise you won't be sorry for doing either of these fun fitness activities. Let's call it what it is, if it's not fun, I'm probably not going to do it... especially when it comes to working out ;o)