Sit on the platform. Press your back firmly against the back of the platform with your feet flat on the floor.
Grab one handle of the machine with each hand. Depending on the model, the pec deck may have a resting pad. If so, place your forearms on each pad. Bend your arms at a 90° angle and keep your elbows at chest level.
Gripping the pec deck handles, pull your arms toward your body while contracting your pectoral muscles. Bring the handles or arm pads in front of your chest, hold the position for a couple of seconds, and then slowly release back to starting position.