2013 Day 27: Desk Chair Hover
Step 1: Stand with your back to your chair with your feet a little farther than shoulder-width apart. Extend your arms in front of you at shoulder level.
Step 2: Lower down slowly, keeping your back straight, until you're almost sitting in your chair. Your knees shouldn't pass your toes, but be positioned over your ankles.
Step 3: Hold the position for 5 seconds and then come back up.
Step 4: Try 2 sets of 10, resting for a couple of minutes between sets.