This is Part 1 of a series of articles detailing the 21 Things Every Internal Martial Artist Should Know about Chinese Medicine, by Tom Bisio.
Virtually everything in the Chinese internal martial arts is congruent with traditional Chinese medicine. All the body principles and alignments are designed to line up the soft tissue, joints and even the organ cavities, so as to maximize free-flowing circulation through the blood vessels and body tissues. Many of the movements common to Tai Ji Quan, Ba Gua Zhang, Xing Yi Quan, Liu He Ba Fa and Tong Bei Quan have the dual purposes of teaching martial techniques with correct body mechanics and simultaneously harmonizing organs and meridians. One of the caveats of this duality is, if you fail to harmonize the organs and meridians, the martial techniques don’t quite mesh properly.
More than one senior master in Beijing has told me: “if you want to understand the Nei Jia, you have to know Chinese medicine.” This does not mean you have to be a doctor of traditional Chinese medicine, but it does mean you need to know a few basic Chinese medical facts and principles. These are easily learned by memorizing a few basic statements. Bob Flaws, a well-known writer on Chinese medicine in the West, calls these “Statements of Fact.” As Flaws points out, these are the basic statements, or premises, that Chinese medical practitioners use to understand, talk about and ultimately practice Chinese medicine.  As internal martial arts practitioners, if we are using these principles in our art, then to some degree we are “practicing” Chinese medicine and we should therefore be familiar with some of the principles that are fundamental to Chinese medicine.
1. Movement and stillness must be balanced.
If the body does not move, Essence (Jing) will not flow. If Essence does not flow, the Qi will stagnate. However, overexertion consumes the Qi, which in turn damages the blood and the circulation. Therefore, it is important to balance training and rest and also to balance the parts of training that are quiescent with those that involve movement. Training stillness without movement leads to stagnation of the Qi. Training movement without stillness overtaxes and imbalances the body.
The balance of movement and stillness must be in accord with the natural world. In Fall and Winter, conserve the energy and lean more towards quiescent training. In Spring and Summer, emphasize movement more and let the body extend and stretch outward.
2. Yin and Yang mutually create each other. Without Yang, Yin cannot transform; Without Yin, Yang cannot engender.
Yin and Yang are inseparable. One cannot exist without the other and each contains the other. Although we can distinguish between Yin and Yang, we only talk about them in relation to each other, never independently. One can only talk about something being “fast” if there is a notion of something being “slow.” Yang action and movement arise from Yin stillness. Movement in the body often revolves around one point that is still relative to the other parts of the body. This is like the moving spokes of a wheel turning around the relatively still hub. In standing still, there are hidden movements and subtle adjustments taking place internally. Relatively Yin substances in the body (blood and body fluids) are like the oil and petrol that lubricate and fuel the movement and functioning of the engine. In turn, the movement and function (Qi and its manifested movements) move and transform the Yin substances.
In the internal martial arts, Yin and Yang are frequently referred to, but the relationship between Yin and Yang is often misunderstood. In Chinese martial arts, teachers often talk about Yin hands and Yang hands. In general, the Yang hand is the hand performing the obvious action, the one that appears to create the desired effect: the strike, the joint lock, deflection, or throw. Often this Yang action is referenced by the name of the move. However, for every Yang action there is a balancing Yin action. The Yin hand supports, assists and “sets up” the Yang hand. Its action is often hidden and unseen. For this reason, it is sometimes called the “dark hand.” In combat techniques, the Yin hand helps to receive an attack, guide, deflect and sense (in this example by deflecting, guiding, leading and drawing) so that the Yang hand can attack at just the right moment, augmented by the force and “set up” of the Yin hand.
However, nothing is completely Yin or Yang. Yin contains elements of Yang and vice versa. Each can also instantly transform into its opposite. This allows the hands and body, and attack and defense to interchange their roles seamlessly and instantaneously.
3. Essence (Jing) is the root of life.
Essence (Jing) is one of the Three Treasures (San Bao) in Chinese medicine and in Daoist body cultivation. Jing underlies all organic life and is the source of organic change, growth and development. Jing is tied to the sexual energy that is the base of the body’s life force. Jing is thought of as a fluid-like (Yin) substance, in contrast to Qi, which is considered to be relatively insubstantial and more Yang. Jing supports and nourishes the body and is the basis of reproduction and development in living things. A necessary part of all transformation and engenderment in the body, Jing is the material that imbues the organism with the possibility of development from conception to death. 
4. Essence and Qi engender Spirit.
The Spirit (Shen) is the third of the Three Treasures. The other two Treasures, Jing and Qi/Breath, must unite for there to be Shen. The Essences of Heaven unite with the Essences of Earth to form Jing.  This is called “the coupling of Heaven and Earth.” In human beings, the union of the Essences of the parents (sperm and ovum) create a new being. This is called the “embrace of the two Essences.” This union of two Essences (two Jing) creates Spirit (Shen), the beginning of a new being. Through the Shen, human beings are capable of perceiving their own experiences and all transformation and change occurring both within and without. Through the Shen, human beings are capable of perceiving the numinous.
Shen is stored in the heart and radiates out through the whole body. The radiance of a person’s Shen manifests through the light, the brightness (Shenming 神明: “spirit brightness”) shining out of a person’s eyes. Thus we can say that a person’s spirit is reflected in their eyes: Bright shining eyes reflect a clear and strong Spirit and a surplus of Qi. Muddy, clouded looking eyes reflect a clouded or imbalanced Spirit and a deficit of Qi.
In practicing the martial arts, as the body moves, the eyes must follow the hands alertly and must manifest Spirit. This trains the Qi and Shen to unite in the martial movements. In combat, the eyes are active, alert and shining as one’s spirit radiates outward. When Jing and Qi unite and are stable, then the heart and Shen will also be stable and calm. These criteria are necessary prerequisites for martial practice, and the reason why much of the foundational training in the Nei Jia is concerned with concentrating and stabilizing Jing and Qi. It is said, when Spirit attacks Spirit, defeat can occur before movement even arises. 
5. Qi is not “Energy.”
What is Qi? There is no single word in the English language that adequately expresses the concept of Qi. Qi can be translated to mean a gas or a vapor, or understood as electromagnetic waves or fields of force. The famous Chinese scholar Joseph Needham felt that the term “Matter-Energy” might most appropriately express the idea of Qi.  For simplicity, Qi is often erroneously usually referred to as “Energy” or “Vital-Energy” It is easy to see why even those that know better fall into the trap of referring to Qi as energy. In English the word “energy” can reference all of the meanings below:
- Vitality or affective force. Vigor.
- An inherent power.
- Function: The capacity of acting, operating or producing an effect, activity and the product or effect of activity.
- The capacity for doing work or the equivalent as in a coiled spring (potential energy) or a speeding train.
- Having existence independent of matter. For example, light or X-rays traversing a vacuum. 
Qi is simultaneously all and none of these things. To understand the concept of Qi more clearly, it is helpful to study the ideogram itself and to look at how the Chinese have conceptualized Qi throughout the centuries. The Chinese character for Qi depicts vapors, curling and rising from the ground to form clouds above.
The ancient oracle bone, bronze or seal form of the character depicts this very clearly:
Later the ideogram was expressed showing vapors rising to form a layer of clouds. This is also part of the character for steam:
The modern form of the character adds grain by using the character mi (rice) which is depicted as: 米. This creates an image of steam or vapor rising from cooking rice.
Various interpretations may be made. It may depict the nurturing energies of rice reduced to their smallest component, a vapor, or, as Needham indicated, the changing states of energy and matter. In early Chinese Texts, Qi is used to refer to various phenomena such as:
- Mists and Fog
- Moving Clouds
- Breathing – Inhalation and Exhalation
Today the simplified character for Qi is again 气.
In relationship to the martial arts and Nei Gong or Qi Gong, breathing is one of the key elements that characterizes Qi. Qi and Breath are inextricably connected, so much so that Qi is sometimes referred to as “the breaths.” Respiration oxygenates the blood and expels waste products such as carbon dioxide. At a cellular level, oxygen is the indispensable key that unlocks the stored energy of ATP. The breaking of ATP’s chemical bonds provides the energy for mechanical work, electrical impulses, cell division, secretion, etc. The connection of oxygen and ATP overlaps with the Chinese concept of Qi and breath, and brings us closer to an understanding, but the concept of Qi encompasses much more.
In common usage, Qi can refer to air, gases and vapors, smells, spirit, vigor, morale, attitude, the emotions (particularly anger), as well as tone of voice, atmospheric changes, the weather, breath and respiration. In the body, Qi is often discerned by its actions, the balanced and orderly vitalities, partly derived from the air we breathe, that cause physical changes and maintain life.  In Chinese medicine, when we say that someone is healthy, it is because the functioning of the their body, the physical manifestations of the their Qi, are orderly and without dysfunction. From this standpoint, every movement, every thought and emotion, our metabolism, every movement of life and consciousness, is in some measure a manifestation of Qi. Benjamin Swartz adds an important element to the definition of Qi when he says: It is also clear, however that Qi comes to embrace properties which we would call psychic, emotional, spiritual, numinous and even “mystical. It is precisely at this point that Western definitions of “matter” and the physical which systemically exclude these properties from their definition do not at all correspond to Qi. 
To sum up, Qi is something that can be felt, internally sensed and understood, but it cannot be seen, measured or quantified. We sense Qi, sense its ability to gather and move; we can sense the breath (and Qi) filling our internal spaces when we do breathing exercises. We can sense the increase in local circulation associated with Qi, and even sense its movement in the meridians. This ability to sense Qi in training, to observe its manifestations and effects is useful, both in improving one’s health and in developing self-defense skills. However, we cannot easily define Qi, so words often confuse the issue. This is why many teachers in the internal arts do not say much about Qi. One should keep in mind that reluctance to talk about Qi, rather than negating the importance of Qi, underscores just how important it is.
 Statements of Fact In Traditional Chinese Medicine (Revised and Expanded) by Bob Flaws, Michael Johnston and Timothy Rogers. Boulder, CO: Blue Poppy Press 2008, p. vii.
 The Web that Has No Weaver: Understanding Chinese Medicine, by Ted Kaptchuk OMD, Chicago: Congdon & Weed, 1983, p.44.
 Rooted in Spirit: The Heart of Chinese Medicine, translation and commentary by Claude Larre, S.J & Elisabeth Rochat de la Vallee. Barrytown, NY: Station Hill Press Inc., 1995, p. 30.
 Nei Gong: The Authentic Classic. A Translation of the Nei Gong Zhen Chuan, translated by Tom Bisio Huang Guo-Qi and Joshua Paynter. Denver: Outskirts Press, 2011, p 71.
 The Shorter Science & Civilization in China: Vol 1, Joseph Needham, Cambridge University Press, 1978. p.239.
 Webster’s 3rd New International Dictionary, Springfield, Mass.: G&C : Merriman Co., 1961. p.751.
 Traditional Medicine in Contemporary China: Science, Medicine and Technology in East Asia Vol. 2, by Nathan Sivin Ann Arbor : Center for Chinese Studies University of Michigan, 1987. pp. 46-7.
 The World of Thought in Ancient China by Benjamin I. Schwartz, Cambridge Mass: The Belknap press of Harvard University Press, 1985. p.181.