How: In a standing position with your feet shoulder width apart and your hands on the back of a chair, table or countertop for balance, bend your knees as if you were going to sit down. Stop a third of the way down and straighten back up to standing, tightening your thigh muscles as you straighten up your body. Concentrate on pushing through your heels and keeping your back upright with good posture. Your knees should move straight forward towards your toes; do not let them collapse towards each other.
How often: Work up to 10 reps, 3 times a day.