The terms jing 精 and qi 氣 are widely used in the teaching of Chinese martial arts. Qi translated into Japanese is ki 氣.
These terms are used to describe physiological experiences, but they are better understood as terms for describing cosmology, and in that role they often have much broader meanings then we are going to address here.
Jing is both the physical body and the mechanisms which reproduce it. As cosmology it is never completely separate from qi; however, fully conceptualized jing is both purity and a purified, uncorruptable essence.
This cuts across normative categorizations in modern thinking, and many English speakers may find it awkward or discomforting.
For instance, jing is simply the entire material aspects of the physical body. It is also the reproductive mechanism which creates scabs for healing wounds, and semen/eggs which reproduces new life.
Extra jing is said to be stored up in the kidneys, and then drawn out when the body experiences trauma or stress.
The term qi has been examined and pontificated on extensively by hundreds if not thousands of experts, so I'll keep my comments brief. Qi is breath of which there are three main types:
- Normal breathing of air in and out of the lungs.
- Whole body breathing, shrinking and expanding all aspects of the physical body, especially joints, and soft tissues.
- Whole mind breathing, accessing one's spatial perception mechanisms as a dynamic way of animating movement.
Qi is both patterns of movement and the qualities with which those patterns are animated. Qi is never completely distinct from jing; however, fully conceptualized qi is both time and the absence of memory.
Again, these are super weird categories for English speakers to grapple with.
Qi is often categorized as a form of energy, but jing is too. For instance, when we eat food, our body extracts the necessary nutrients from it, those nutrients can be categorized as either jing or qi or both, because all food is a mix of jing and qi. If the nutrients go to heal something, we could say the food is more jing-like, if they go into exercise we could say they are more qi-like.
Alright, I just needed to get all that out of the way.
Many schools of Daoist inspired martial arts and meditation will explain that we are cultivating qi, as a general description of many different methods. They will also refer to storing qi in the dantian 丹田. This is confusing because if we think of the dantian as being somewhere around the belly area, it is hard to distinguish from fat. The confusion arises because 150 years ago hardly anyone had enough food, so if you could store up some fat, you were doing great. The two meanings of dantian became conflated. Dantian in the Daoist and martial arts sense is not a location on the body, it is the center of a form of awareness. So cultivating qi actually meant cultivating a type of awareness of available resources--resources which are actually intrinsic to being human. The simplest one of those resources, the easiest one to understand, is balance; For example, the ability to spontaneously recover a feeling of central equilibrium when someone gives us a sudden and unexpected shove from behind. But there are many other intrinsic resources in this category.
So getting back to the title of this post, can we transform qi into jing, or jing into qi, and is either one more or less desirable than the other?
The way we move, any type of action, has an effect on our physical body. So moving with a specific type of awareness of what or how that movement will change our physical body, is transforming qi into jing. But consider that two people doing what may appear to be the exact same exercise routines do not necessarily get the same changes in their bodies. The concept of transforming qi into jing implies the exact totality and specificity of the complete mental, physical and emotional processes by which movement changes our physical bodies.
So what about the other half of the equation, transforming jing into qi? In order to be good at jumping, for instance, one needs to have the right underlying structures established in the body. With an injured knee or back, one's jumping capacity can be severely limited. We have already established that it is jing which heals us. Modern people might say that blood transports new cells and carries away old ones, but the truth is the process of healing is intensely complex. So using the term jing to refer to the totality of the healing mechanisms and substances is not so difficult for a modern person to grasp. Once the body structures are established (via "qi" training) or repaired (via healing) we spontaneously have the ability to jump! Our jing, our physical structure, simply has the capacity to manifest as new movement patterns, also called qi.
So jing transforms into qi effortlessly, it is a spontaneous process. The same is true for meditation practices. In stillness jing transforms into subtle forms of qi. Subtle movement simply arises. It is generally invisible to an outside observer, because that movement (qi) is happening either inside the body or is perceived by the meditator as happening outside the body.
Now you know the answer to the question in the title of this post!
While modern people often find ways to discard these terms the unique categorical lines these terms implicitly create, open up ways of thinking about body and awareness that may not be directly accessible through conventional notions of physiology.
After I wrote everything above I did a google search for "transforming jing into qi" and at the top was this rather poorly informed debate, so I hope this post clears things up a bit.