Kipping begins with two body shapes: the hollow position and the tight arch position. These are universal body positions that apply to any gymnastics skill. Once you learn how to perform these positions kipping becomes fluid and effortless.
The hollow body position has much more application than kipping alone. It is a tool used to teach proper bracing. When moving under load or through space you need to create stability in your abdomen which allows the rest of your body (your extremities) to safely go through ranges of motion. In the context of kipping, a strong hollow position creates opportunity for better control and “snap” when kipping. During actual bar work you are in a hollow position when your body is behind or directly underneath the bar. You can practice this position using floor drills. The following steps show how to correctly build a hollow body position beginning with a basic shape called the “tuck and reach.”
To begin, lie on your back with your legs straight and in front of you. Press your low back down and into the ground. This should cause your abdomen to tighten up and feel secure.
While maintaining your low back on the ground, bring both knees towards your chest while keeping them together and point your toes away from your face.
Bring your shoulders off the ground and gently tuck your chin towards your chest. Raise your arms off the ground so that they contact your mid-thigh with elbows straight and palms down. Your low back should remain flat on the ground. This is critical! If your low back isn’t flat to the ground then your core isn’t braced!
Once you can accomplish a tuck and reach you can progress further into a hollow body position by straightening out your legs one at a time. Make sure that at the point of full knee extension your foot is at shoulder height with your toes pointed away from your face. Squeeze your butt to secure your hips.
If you can maintain your low back while keeping both legs out then reach your arms above and behind your body as if you were hanging from a bar. You can also perform this motion while holding a PVC pipe.
Your low back must remain flat on the ground during all phases of a hollow body progression. If at any time you “lose your lumbar” (meaning your low back arches off the ground) then go back to the previous step and work from that position. Only progress if you can maintain each position for 20 seconds unbroken.