Our Nose Knows Best
In...out...in...out. Good. Now let’s talk about breathing.
If you’re reading this, you’ve been breathing on your own (hopefully) since the minute you were born. Inherently simple, it is one of the several autonomic or unconscious processes that keep us alive from one moment to the next. But just because the act in and of itself is simple, the results of each breath are significant.
Despite the ability to breathe through either our nose or mouth, how we breathe matters a great deal. Anatomically speaking, our mouth is intended for eating, drinking, and speaking while our nose is designed for breathing. However, some estimates say that as many as 30-50 percent of adults regularly breathe though their mouth. Quite simply, this was not what nature intended.
A Tale of Two Breaths
A breath through the mouth does not compare to that same breath inhaled through our nose. Whether training for endurance sport or simply striving to live a healthier life, there is no shortage of advantages to nasal breathing. Unlike the mouth, our nose warms, moistens, and filters the air we breathe. These passive benefits help to prevent colds and flus and promote activity of the parasympathetic nervous system that calms our bodies. Perhaps what sets nasal breathing apart from the mouth most though is nitric oxide.
Discovered in 1998, nitric oxide is a signaling molecule in our cardiovascular system. A powerful bronchodilator and vasodilator, it lowers blood pressure and, particularly relevant to endurance performance, increases our lungs’ ability to absorb the oxygen contained in each breath we take.
Not only is oxygen more readily absorbed by the lungs when breathing through our nose, each breath literally contains more oxygen. Thanks in part to intricately dense nasal passages, the nose provides more resistance to the air stream than mouth breathing. This resistance encourages elasticity of the lungs and results in upwards of 20 percent more oxygen with each breath.
Important as oxygen is, it is far from a lone actor. Unfairly labeled a waste product, carbon dioxide often gets a bad rap, to be exhaled with reckless abandon. In fact, carbon dioxide is instrumental in regulating many important functions associated with endurance, namely the release of all that oxygen in the tissues. Our lungs require about 5 percent carbon dioxide. Given our atmosphere contains only a fraction of this (0.03 percent), our bodies are responsible for producing and storing enough in the blood and lungs to make up the difference. Known as the carbon dioxide partial pressure, this delicate balancing act helps regulate the amount of oxygen in our blood.
Release the Oxygen!
Oxygen is transported through our blood with the helping hand of a protein called hemoglobin. As the carbon dioxide partial pressure rises, the bond between oxygen and hemoglobin weakens, making oxygen more readily available to be absorbed by our muscles and tissue. Alternatively, reducing the carbon dioxide partial pressure strengthens the bond, resulting in less oxygen availability throughout the body—every athlete’s worst nightmare. Considering each of us is beholden to this system the question then arises, does it matter how we exhale?
We know a breath through the nose contains more oxygen than the same breath through the mouth. Similarly, each exhale through the mouth releases more carbon dioxide, lowering the carbon dioxide partial pressure. It then follows that, during peak output, while huffing and puffing with mouths agape, we are in effect making it more difficult for oxygen to reach our muscles. Consider then the effect our breathing has on our VO2 max.
The term VO2 max gets thrown around a lot in sport and is a crucial metric for understanding one’s endurance capacity. A bit nebulous even to those already familiar with the term, an athlete’s VO2 max is best understood as the aerobic capacity of our muscles. Essentially it is a measure of the maximum performance level before our muscles begin using oxygen faster than the blood can restore it. So, if we are regularly breathing through our mouths while training, we are in effect inhaling less oxygen while exhaling carbon dioxide at a rate that only makes the little oxygen we receive less bioavailable.
Endurance assets aside, the benefits of nasal breathing are ready to be realized in each of our daily lives. In an article published in Nursing in General Practice, Dr. Alan Ruth was keen to point out many ways in which breathing through our nose helps maintain overall health. From the natural defenses our sinuses provide, to the antiviral benefits of nitric oxide produced in the nose, a return to nasal breathing quite simply means a healthier population. So, it’s time to celebrate our nose for the lifesaver that it is. Now, let’s take another deep breath, this time through your nose.
For those looking to adopt healthier breathing habits, here are some useful resources:
Taping your mouth closed at night helps encourage nasal breathing during sleep. While the name is a bit unsettling, Hostage Tape sells small flexible strips designed to cover the mouth while you sleep.
Yoga and meditation adjacent, developing a regular breathwork practice can help us connect our breath with our body. While local options may prove limited in some areas, Op e n is an online wellness studio that offers regular breathwork courses. Click my referral link for a free month.
Spoiler alert: I have only scratched the surface of the benefits of nasal breathing. Interested in some further reading? James Nestor’s book, Breath, offers insights both historical and scientific as to the role our nose has played in our evolution and overall health.
