Pull-up purists will have one answer, and CrossFitters will have another. While you may not consider it cheating to kip your pull-up, it does offer a lot more mechanical stress — and therefore pose a bigger injury risk — than strict pull-ups. While no two lifters are going to have the same opinion, a good rule of thumb is that you should look at kipping as a skill in and of itself — and you probably shouldn’t tackle that skill until you’ve fully mastered the strict pull-up. On the other hand, if you’re trying to kip to “achieve” your first pull-up, you probably want to back it up and build to a strict pull-up.