Attach a pair of resistance bands to a door anchor and place the door anchor at the top of a door. Attach the workout bar to the other ends of the resistance bands. Sit on a bench or an exercise ball. Grab the workout bar with overhand grip. For a wide grip, your hands need to be spaced out at a distance wider than your shoulder width. For a medium grip, your hands need to be spaced out at a distance equal to your shoulder width and for a close grip at a distance smaller than your shoulder width.
Pull down the workout bar to upper chest. Return until arms and shoulder are fully extended. Repeat.
Range of motion will be compromised if grip is too wide. The upper torso should remain stationary and only the arms should move.