Jillian Michaels: genius.

If you're looking to shake things up a bit and try a new routine, I suggest giving this DVD a try. I tried this for the first time yesterday. O. M. G. I am so sore today! It really feels like it's working, even as your're doing it--plus, it's only 20 minutes! There are 3 levels, so you should be able to mix it up for quite a while without getting bored. And, hey, if you really do lose up to 20 pounds in 30 days... I'm in.

- Kristen

Get yours here: Jillian Michaels: 30 Day Shred at Amazon