Knee squeeze Step 1: Sit up straight in your chair, with your feet shoulder-width apart.Step 2: Place a water bottle, handbag, sweater, book, or some other object you have got hanging around the office, between your knees.Step 3: Tighten your abdominal muscles.Step 4: Squeeze the bottle or other object with your thighs.Step 5: Release the squeeze (although not so much that you drop the bottle).Step