We all remember Mom telling us to chew our food slowly. Why? Because it promotes proper digestion by allowing the digestive enzymes in the saliva to start breaking down your food at the beginning of the digestive cycle. Similarly, proper breathing can also affect our biology.
Bikram yoga promotes nasal breathing during the majority of its postures (24 of 26 poses). For instance, the first posture (Standing Deep Breathing/pranayama) and the last posture (Blowing in Firm Pose/Kapalbhati in Vajrasana) incorporate both nasal and mouth breathing for several reasons.
Standing "Deep Breathing" helps prevent respiratory problems such as bronchitis, emphysema and shortness of breath. "Blowing in Firm Pose" improves digestion and circulation, and increases the elasticity of the lungs with every forceful exhale (this is the same theory behind the spirometers that are used in hospitals for post-op patients). This posture also strengthens the abdominal organs and increases circulation to them.
Everything we do affects our biology, be it eating, exercising, sleeping … or breathing.
So what’s the big deal about breathing through your nose and not your mouth? Nasal breathing is an extremely important part of your 90-minute Bikram yoga session. Basically, it comes down to how our breathing affects the carbon dioxide (CO2) levels in our lungs and blood. It has very little to do with oxygen levels.
Proper carbon dioxide levels, which regulate the healthy narrow pH range of the blood, allow for the adequate release of oxygen to our tissues and our brain. Many of us, throughout our lives, have been given the vague impression that CO2 is bad for us. Quite the contrary — without CO2 we wouldn’t get the oxygen we need. Proper CO2 levels are what trigger our red blood cells to release the oxygen they carry.
Most of the CO2 that we use actually does not come from the atmosphere; our own bodies manufacture it as a byproduct of natural bodily processes. Therefore, if we aren’t breathing correctly, then we’re also not producing the proper levels of CO2 in our bodies that we critically need.
Consider, as an example, a can of soda. We’ve all enjoyed a nice cold soda on a hot day; it’s full of sparkle and life and fizz. We’ve all also experienced what happens when you leave an open can out for a while. You come back and the drink is now flat; it’s lost its fizz.
What’s in a can of soda? Water, salts, sugars, coloring … and CO2 (hence the term “carbonated beverage”). Interestingly, blood contains the same main ingredients ... water, salts, sugars, coloring (from the hemoglobin in our red blood cells) and, again, CO2. What would happen if our blood lost its fizz?
So how does all this work?
The lungs store CO2. If carbon dioxide levels fall below a certain level of pressure, we start to experience imbalances, which turn themselves into symptoms. The brain is set to trigger breathing through the diaphragm as long as there is adequate carbon dioxide levels in the lungs. You will achieve and maintain the proper level of carbon dioxide as long as you breathe functionally.
Functional adult breathing is 8-10 breaths per minute at rest, in and out through the nose, not through the mouth, driven by the diaphragm, not by the upper chest. Most importantly of all, breathing should be silent. If breathing can be heard, it’s not functional.
Why nasal breathing?
Because noses are made for breathing!
They have a four-stage filtration system: