Soldiers in China, singers, and external martial artists often practice chest breathing. This involves breathing practices that expand and contract the chest and ribs, and develops the strength of the upper lungs. The practice of yelling or exhaling qi through the mouth when practicing martial arts also practices the qi of the lungs. However, these types of breathing are not a part of typical Daoist or internal martial art practice. The Daoist conception of the body tells us that the qi (气) or "intrinsic energy" in the body naturally moves upward. We believe that practicing chest breathing encourages this tendency. When the qi in the body is raised, it is best to do the jumps and flips that are common in the external arts. However, if the qi in the body is high, a person will also feel unsettled, like a tiger in a cage, they will have a bad temper.
In the internal arts the qi of the chest is compared to fire and a tiger. The qi of the stomach is compared to water, or a dragon. Our traditional Daoist practices involve grounding the qi low within the body instead of raising it. When the energy of the chest and the energy of the belly are able to mix, this is called 'mixing fire and water'. As everyone knows, when fire and water are mixed, they create steam. This steam (qi) creates more energy for the body. This type of metaphor is common in the Daoist internal arts practices, where the body is compared to a crucible (stove for making medicine) where fire and water create steam (more qi for the body).
The role of the mouth in the internal arts related both to Confucian and Daoist theory. Confucian thought teaches that the mouth is the source of many problems. We have a traditional saying meaning that "trouble exits from the mouth, and sickness enters." This refers to the problems that saying the wrong thing, or eating and drinking unhealthy things can cause. However, the mouth is also necessary for preserving life. Ideally, it should be used for nourishing qi. This means when we eat and drink, we should do so in a way that brings energy to the body. Daoism teaches that talking too much can exhaust the body's energy and vitality. This is why all religions have a practice where people take vows of silence. When I first leaned these techniques, I tried them out by walking around the outside walls of the temple with my mouth wide open. I found that I got tired a lot easier. This is something you can try out for yourself.
Preventing excess energy from exiting the mouth spans the Daoist meditation and martial practices. For this reason, I was taught that it is bad to expel breath through the mouth while practicing. The reason for this is because the energy and breath in the body should be conserved. If too much qi is exiting from the mouth, it will weaken your punches, and you will tire more quickly. Also, if you are making loud noises while practicing, it is easy to become self-conscious about what noises you are making, and how loud they are. How many people have found themselves embarrassed because they are making more noise than the people around them. When this happens, your mind is drawn away from where it should be. Click to learn how Chinese medicine treats Stroke (Apoplexy).
It is said that in the internal martial arts, we use qi when we practice. It is important to remember that qi does not just mean 'breath'. Rather qi refers to the material energy of the universe. It is the air we breathe, and the food we eat. It is also given to us from our parents before birth, and taken in during our interactions with people. Qi refers to anything intangible but perceptible, things you can feel easier than see. However, while it is easy to think of Qi as an energetic substance, it is also correct to think of it as a process. In Chinese medicine, Qi is most commonly defined not by what it is, but by what it does. This is similar to the conception of energy in modern physics, where matter is describes as having an interconnected physical and energetic qualities. Qi is that which warms, raises, and harmonizes, as well as the process by which things are warmed, raised up, and harmonized. This material energy works in many ways, creating movement, and nourishing the body. Nourishing your body's qi can be done by practicing breathing techniques and meditation, eating and drinking nutritious foods, keeping your interpersonal relationships healthy, and working to create a clean environment.
When a martial artist uses qi it also refers to a process. For me, this process begins by keeping the breath in the body low, and emitting force through the entire body. When I practice, I breathe deeply into the abdomen, and fill the dantian. When I emit force (fa li), I am breathing out from the dantian, through the nose (which lets air out slower than the mouth, hence avoiding letting out too much qi). While the mouth exists mainly for the intake of nutrients, the nose was designed to be the main organ of respiration. The dantian is also kept full on the exhale, and my mind (yi) is focused on using the qi and strength from my lower body and waist. In this way, whole body movements are used. This means using the legs, dantian, and waist area to emit force, and keeping the mind focused on where the force is going. The mind, breathing, and body are all in harmony. When the body and mind are synchronized, the qi of the body will harmonize with your movements naturally.