I used to use the Wii Fit when Zander was sleeping, he doesn't anymore, so that's out. Maybe you could try something like that, or get an exercise DVD to try.

Another good tip I've heard, but never used myself is The Wiggles exercise method (LOL). What you do is put on a Wiggles DVD and copy all of the dance actions for the duration of the DVD. It will give you a pretty good 30-60 minute workout & I'm sure DS will enjoy it too