The following is a very simplified explanation of the mechanics of breathing. To get this kind of understanding may help you develop greater awareness of what you actually do when breathing.
There are 3 basic ways to breathe. Some are better adapted to different types of activity.
Read this and experiment. In a later post I will propose some basic exercises.
Basic Architecture of the Torso :
The Chest at the top contains the Lungs and Heart. The Chest is a cavity formed by the spine in the back, the sternum in the front, and 12 pairs of ribs on the sides.
Under the Chest the Abdomen contains the digestive organs : stomach, liver, spleen, pancreas, intestine; the kidneys and bladder, and the reproductive organs.
Chest and Abdomen are separated by the Diaphragm, a flat muscle shaped as a dome. In the center of the diaphragm is a hole through which run the esophagus and some veins and arteries. The shape of the diaphragm is modified during breathing. Inhalation corresponds to a flattening of the diaphragm.
The lungs located inside the ribcage have the general shape of a bell. Their structure is similar to that of a sponge and they are elastic. Muscular action can stretch or compress the lungs, (exhalation or inhalation). When the muscular action ceases, the lungs revert to their original shape and volume. If you try to force yourself into inhaling lots of air, and then relax, your lungs will naturally empty. If you try to force yourself into emptying your lungs as much as you can, when you relax, air will naturally fill them up again.
The digestive organs in the abdomen are not elastic. Their shape and position can be changed by muscular action, but not their volume. Separated from the lungs by the diaphragm, they act as a sort of piston which can move up or down under the lungs, pushing or pulling them up or down.
There are 3 basic ways to modify the shape of the lungs :
- lifting or lowering the chest.
- expanding or squeezing the bottom of the chest.
- raising or lowering the digestive organs.
- Lifting or lowering your chest : Inhale by raising your chest : straighten your spine and lift your ribs; exhale by letting your ribs fall and rolling your spine down. This is the shallowest kind of breathing, there is not much room for expansion of the top of the lungs.
- Vary the diameter of your chest. By expanding or squeezing your lower rib cage sideways. This is a deep way to breathe. The ribcage can expand quite a bit sideways, and the bottom of the lungs can expand a lot to inhale lots of air.
- Upward or downward movement of your abdominal organs, through action of your abdominal muscles..
Exhalation happens by contracting one's lower abdominal muscles. This action lifts the guts. They push the diaphragm and the lungs upward. This type of breathing is very adapted to intense activity such as fighting where emphasis should be made on short forced exhalation through contraction of the abdominal muscles. Inhalation just happens by itself in between each exhalation.
Inhalation is produced by contracting the higher abdominal muscles. This pushes the guts downward, which pulls the diaphragm and the bottom of the lungs down. This way of breathing is less common. It does not allow for a very deep breathing, because the same action that pushes the guts down also limits the ability of the chest to expand laterally, but for some non-mechanical reasons, it is very interesting for meditative purpose.
Of course, it is possible to combine these actions, and practically we very often do it. For example, when we are out of breathe, we combine lifting and lateral expansion of our ribcage in order to inhale huge quantities of air. Or when we sneeze, we roll our spine to the front to lower our ribcage, and contract all muscle groups that squeeze the chest and push the guts upward.
In a later post, I will propose a few exercises. for now I suggest you try to figure these 3 modes out by yourself.