It was mentioned in an earlier posting that kids need a minimum of 15 minutes to improve their health. So, here's a quick idea that is a blast for the younger kids and fun for the parents, too. Take them to a softball diamond for kickball. Parents, play with the idea of keeping them running. I hammed it up with my three younger ones for 30 minutes. No points, all of us running, having fun, and gettin fit.
Try it and please share your experience with it.