Kipping pull-ups are an essential element of gymnastics training, and of CrossFit in general, having originally evolved as a way to perform pull-ups in a more efficient manner, generally resulting in the ability to complete a higher number of reps. The skill is now used throughout WODs and competitive CrossFit for the very same reason.
Kipping uses lower-body momentum to help pull your body to the bar. By reversing their hip direction or creating a ‘swinging’ motion during the movement, athletes are generally able to complete the pull-up using less energy and strength, allowing for more reps to be done more quickly. This is a highly useful technique for those competing in CrossFit or completing an AMRAP workout.