An easy way that I have found to add a little more movement to my life is during recess. Two of us are on duty, so I join in on that game of or while my partner supervises the jungle gym. The kids LOVE it, are less likely to mess around, and I get a mini workout in. I have even started just going to recess to play a quick game when my head is all cloudy and I need to refocus for the afternoon.
Just make sure you have a good pair of tennis shoes on those days...and deodorant in your desk.