Today I came across this fun site Kidnetic.com that's geared towards fighting childhood obesity by getting kids up and moving. Being the competitive (and sometimes childish) gal that I am, I immediately played all the games and was drawn to the fitness challenge.
The fitness challenge is 10 challenges/exercises that you (or your kids) complete while being timed (things like run to the bathroom and back, hop on one leg, etc.). Sure it's for kids, and your coworkers may think you've lost it, but I felt great after doing it. I did mine in 2:31 seconds — I could have been faster but the bathroom is really far away from my desk here at Sugar HQ. Can you beat my score? I bet you can't.
Not acceptable to do at your workplace? Try it at home. If you have kids, pass it along to see if you can beat them.