The problem: Not completing the full range of motion.
Most people fail to straighten their arms fully at the bottom of the pull-up (a position called a dead hang), and many fail to pull themselves high enough as well. This robs you of much of the muscle-building potential of this always-effective, super-tough exercise.
How to fix it: …is pretty obvious — try to pull your upper chest to the bar (or at least your chin), and lower yourself all the way back to a dead hang during each rep.
If only it were that easy. While one of the more common exercises, the pull-up is still one of the toughest bodyweight moves most gym-goers practice regularly: an informal online poll suggests that the average man can perform just one pull-up; the average woman not even that. Talk about an ego check.
The key to doing multiple pull-ups, as with any other exercise, is to reduce the weight you’re using. On the pull-up, you can accomplish that with a Chin-Up Max assistance band, which hooks onto the pull-up bar and loops around your feet. As you lower your body, the band stretches — giving you more help on the way up.