Grasp the pull-up bar with a shoulder width underhand grip.
Now hang with your arms fully extended and stick your chest out and lean back. Tip: You will be leaning back throughout the entire movement. This will be your starting position.
Start pulling yourself towards the bar with your spine arched throughout the movement and your head leaning back as far away from the bar as possible. Exhale as you perform this portion of the movement. Tip: At the upper end of the movement, your hips and legs will be at about a 45-degree angle to the floor.
Keep pulling until your collarbone passes the bar and your lower chest or sternum area touches it. Hold that contraction for a second. Tip: By the time you've completed this portion of the movement; your head will be parallel to the floor.
Slowly start going back to the starting position as you inhale.
Repeat for the recommended amount of repetitions.
Variations: You can perform this movement using a chin-assist machine if unable to do it without aid or have a spotter help you up. You can also use the pull-down machine instead even though due to the fact that the pull-down machine does not involve a lot of the stabilizer muscles needed for the chin-up, the exercise becomes less effective. Also, as you get more advanced, you can use a weight belt to increase resistance.