STARTING POSITION:
Select the appropriate plates amount to put them on the bar of the smith machine. Lie back on a flat bench, your eyes should be under the bar. Your feet should be touching the floor. Grab the bar using a prone grip slightly wider than shoulder width apart. Lift the bar just a little and twist your hands to un-rack the bar. Extend the elbows and lift the bar up off the rack and hold it straight over you with your arms locked.
MOVEMENT:
Lower the weight down slowly to the chest while you breath in. Push the bar back to the starting position while you exhale. Repeat the movement until all repetitions are completed and then re-rack the barbell.
TIPS: Focus on push the bar with your chest muscles and squeeze the glutes when you do it. If you are a beginner at this exercise, use a spotter. If no spotter is available, then be conservative with the load that you use.