Keep your abs tight, and press your lower back firmly against your seat for support.
Press the inside of your knees against the support pads in a stretched position.
Press your heels into the grooves between the foot support posts at the bottom of the machine.
Using your inner thigh muscles, exhale through your mouth as you squeeze the weight all the way in to touch in the center.
Inhale through your nose as you return to the stretched position.