Grab the pull-up bar with the palms of your hands facing inward. For a medium grip your hands should be spaced at shoulder width. Both of your arms should be extended in front of you while holding the bar at the chosen grip. You want to bring your torso back about 30 degrees while creating a curvature in your lower back while sticking your chest out. This will be your starting position. Now exhale and pull your torso up until your head is above your hands. Concentrate on squeezing your shoulder blades back and down as you reach the top contracted position. After a brief moment at the top, inhale and slowly lower your torso back into the starting position with your arms extended.