hula hooping:

Your first hula hoop workout plan: hula hoop for 30 minutes.
Once this becomes too easy: hula hoop for up to 90 minutes and/or use a weighted hoola hoop.
For the best workout: Adrian recommends hoola hooping for 1 minute, jogging in place (or jumping rope) for 1 minute, and then repeating both over and over for 10-30 minutes.