Stand up and push your chair back out of the way. Rise up on your tiptoes as your breathe in, then slowly return to a flat-footed position as your breathe out. Spend about two seconds going up and about four seconds lowering your heels back to the floor. Repeat 15–20 times, rest a minute, then do another 15 to 20.
Got Something More Advanced?
Try the exercise on one leg. Lightly touch your desk with one hand to maintain balance, tuck your left foot behind your right ankle and do 15–20 of the above with the right leg. Reverse position and repeat with the left leg.