Peter Hjortsø, unaffiliated crossfitter based in Vietnam (former CrossFit Copenhagen)
Pull-ups play a vital role in CF (we do many of them) and to the novice CFer understanding how 100 PU can be accomplished during a WOD can be hard. It´s all in the kip. Moving the hips back and forth to create momentum to aid the pull-up.
1. Move the hip. Not the legs.
Start by standing on the ground with your legs about hip width. Then move your hips forward and backwards. Do this to feel and understand what should be done when you are hanging from the bar. The essence to understand here is really that your feet should not move very far away from the spot over which they are placed when hanging.
Now hang from the bar. Start by carefully moving your hips back and forth as you did while standing. This may not be so easy at first. Often the legs will start swinging leaving the hip almost over the same spot on the floor. If this happens let go of the bar and re-grip it so that you hang still. Repeat the hip movement.
2. Kip violently.
Make sure your hip reaches the outer positions when swinging back and forth this will enable you to do more pull-ups.
3. Pull and and push.
When you have reached the outer back position and are almost looking over the bar pull yourself towards the bar. Once you have had your chin over the bar push yourself away from it while pushing your hip forward.
4. Take it easy.
Accomplishing many pull-ups is most easily done by going a nice steady pace. Do not rush it as this will make you short for breath faster and start the anaerobic process in the muscles.
The only way to become really good at pull-ups is to do a lot of them and experiment with the kip. Many experienced Crossfitters are available to give advice on this.
5. Listen to your body.
If you experience sore muscles – especially the biceps – swelling of the muscles go to the Emergency room at the hospital immediately. Especially if this occurs 2 days after doing a workout with many pull-ups. Should you experience dark urine before this go to the emergency room. This may very well be rhabdomyalysis. Tell them this at the emergency room. It is a potentially life threatening condition that can only be alleviated in a hospital.