Notice that the kip is minimal and head movement is non-existent. Athletes can tend to get a little overactive when it comes to kipping pull ups. The kip allows us to generate dynamic energy but also breathe. They can’t breathe if they’re moving their head back & forth. Relax and let physics do the work. They should only pull when it is appropriate. I feel sometimes both athletes are rushing their kip to get to the pulling. Sometimes the kip needs to finish before we begin the pulling.