Major compartments of the body
There are many different kinds of Chi, but simply, it is Breath.
Think of your body as a series of bicycle tubes of different sizes, making up compartments and meridian ways throughout. When we breathe with our abdomens (Diaphragmatic Breathing), it is like the pumping action of a bicycle pump; breathing in fills the chamber (lungs) with air, breathing out sends the air into the tubes (organs and meridians). Naturally the tubes lose air and need to be pumped up again (most of us are not doing Diaphragmatic Breathing 24/7).
Anxiety, hypertension and high blood pressure, is like having tires with pressure that is too high for it's design. The internal pressure presses up against the confines of the compartments effected and POP ! Other conditions of over inflation are: over-sensitivity, poor circulation, pain, increased body temperature, skin problems, etc.
If our meridians are not filled enough, you probably experience fatigue, low blood pressure, numbness, poor nerve conduction, decreased immunity, and hormone irregularities, for starters.
Most of us have an imbalance in the system - some are overfilled and some are under filled. One of the reasons being is that most people are in their heads and that's where the breath goes. In Chinese Medicine, the Yi (intent) , leads the Chi (breath), and the Chi leads the Li (gross physical body - muscle power). So, where we put our intent, is where the Breath goes; if we are breathing in one area/ compartment most of the time, the others will suffer with no nourishing Chi.
Another major reason for imbalance is the tire tubes/meridians in the body can accumulate debris inside causing bottle necks in the flow of Chi (air). Again, if the vital breath that keeps us healthy, alive, and aware is slowed down or cut off completely, major pathological conditions can manifest.
You might say: "but the lungs are in the chest and that's where I'm breathing."
This is true, but looking at babies who are natural belly breathers; their Mind/Body connection is unbroken, and vitality strong. They haven't been conditioned out of their natural state -yet. If they are upset, the breath is quick and shallow - Wah ! When relaxed they are truly 'resting and digesting'. Think of when you first wake up from sleep - slow even breaths can be noticed, a sense of calm also. As soon as the first thought about what you have to do that day arises, the nervous system reverts to 'fight or flight'.
Breath control is Chi control. The main muscle in respiration in the body is the Abdominal diaphragm - without this being engaged we end up overusing the muscles of the neck and chest, resulting in neck and chest tension. If we are engaging the pelvic diaphragm when we breath the power of our breath capacity is exponentially improved ( a technique taught in Qi Gong or can spontaneously happen in meditation.) If the breath can deepen and sink lower in your body, your organs get toned, more oxygen can reach your every cell, and emotions become grounded. This is how regulation of breath is the key to regulating the mind and body!
In Bodywork we seek to improve diaphragmatic breathing because healing cannot happen without Cellular Respiration ( Oxygen metabolized by cells to create energy!! ). This is the action of Chi.