The complement to the hollow body position is the tight arch position. This is the position we use to create stability when the body is in an extended body position. The tight arch refers to your body when it is in front of the bar right before you transition back to a hollow position. We can recreate and practice the tight arch using floor drills.
Begin by laying face down on your stomach with your legs straight behind you and your arms straight in front of you. Then, while keeping your feet together and arms straight, raise your feet and arms off the ground while squeezing your butt. It is important to keep the feet together because they play a key role in maintaining solid body mechanics in gymnastics. You want to reduce any excess movement that could reduce hip/core stability. This is very apparent when suspended from a bar or rings. Because your feet are no longer connected to the ground, you have to create stability by keeping your feet together and connecting your body in one solid piece.
Now tighten even further by lifting your chest and thighs off the ground. Your goal is achieve maximal activation through your posterior chain. Doing so will directly impact your ability to absorb and then redirect the power needed to transition behind the bar. While doing this, keep your eyes down to avoid lifting your neck excessively. Lifting your eyes and/or head causes unnecessary cervical spine loading which makes it very difficult to properly recruit your core muscles.
The tight arch is generally easier to perform than a hollow body, but must be executed correctly to have any transfer to kipping. Done correctly this drill should activate your entire posterior chain simultaneously. Having better control of your posterior chain allows for smoother transitions from a hollow body position to a tight arch position and reinforces proper body alignment through bar and ring work.
Along with the hollow body position these two movements are fundamentals for not only gymnastics movements, but overall core stability. Incorporating these two drills into your warm-up or coll down can make dramatic improvements to other aspects of training. Strengthening your core takes train off of your back and improves overall motor function and mechanics. Use these drills as a supplement to your current training and build confidence in your gymnastics.