This is a slightly more advanced exercise that helps develop balance and stability as well as endowing all the leg muscles, but especially the quadriceps muscles and the gluteals, with considerable strength.

1 Stand tall, a small distance away from the machine, with your feet hip-distance apart and your toes pointing forward. Hold the handles so that your palms are facing each other, and flex your arms fully at the elbow. 

2 Pull in your abdominal muscles, but not so tightly that your breathing is affected. Inhale and slowly lower your body - start the movement at your hips by pushing them out behind you in a sitting motion, then allow your knees to bend, but make sure that they do not travel forward over your toes. Continue lowering your body until you are in a comfortable position but ensure that your knees do not bend inward or bow outward and your feet, knees and hips are in line.

3 Exhale and slowly push up through your heels, maintaining good posture all the way up through the movement.