Make sure you use a full range of motion. Pull up until your chin is above the bar, and lower yourself back down until youre almost hanging with your arms straight.
Control your motion throughout the exercise, and dont let your body drop quickly. Slow and controlled movement will get the best results.
Instructions
The close grip pull up is a variation to the wide grip pull up, just using a closer grip. Grip the pull up bar with an overhand grip and hand about 10-12 inches apart.
Take your feet off the floor so that you're hanging from the bar. This is the starting position.
Slowly pull yourself up until your chin is above the bar, and then slowly lower yourself all the way down to the starting position.