I set a timer if I am sitting on the couch or at the dining room table. My watch timer, at 25 minutes, does the trick. When it buzzes, I stand up. Sometimes I bounce a little on the mini-tramp or wander out to the yard, but I always make sure I'm up for at least a minute. As a writer, I have to do this or I can sit for hours! I also only get up using my legs, never the chair arms. It's minor, but making sure your leg muscles work is very important. They are the largest muscles in the body.