By Jared Packer
There are many important benefits to nasal breathing, yet, how often do we actually notice our breathing? Pay attention to your breathing for a moment - are you inhaling through your nose or you mouth? If you’re not breathing through your nose, you may have a breathing pattern dysfunction. Think about this - How does a stressed person breathe? How does an unwell person breathe? Slow, rhythmic breaths through the nose? Or fast chest breaths through the mouth?
Before we get to benefits of nasal breathing, let’s focus on the characteristics of Mouth breathing:
Sympathetic nervous system drive (“fight or flight”)
Primarily chest breathing
Uses secondary breathing muscles
Constriction of blood vessels in the lungs
Decreased oxygen exchange from lungs to the blood
Increased breathing rate
Poor sleep quality
On the contrary, nasal breathing has the following characteristics:
Parasympathetic nervous system drive (“rest and digest, tend and befriend”)
Primarily diaphragmatic breathing
Dilation of blood vessels in the lungs
Increased oxygen exchange from lungs to the blood
Decreased breathing rate
Humidifies air
Sterilizes air
Improved sleep quality
Let’s examine why each of these are important.
(credit: Backyard Brains: https://backyardbrains.com/experiments/ Sympathetic_Nervous_System)
Our Autonomic Nervous System has 2 main branches, Sympathetic and Parasympathetic. The sympathetic branch is responsible for our “fight or flight” the response, whereas the parasympathetic branch is responsible for the “rest and digest, tend and befriend” response. Basically the sympathetic branch gets you fired up and primed for movement, and the parasympathetic branch puts the brakes on and chills your body out.
Two-way communication exists between the nervous system and breathing. Any time we are stressed, our breathing rate and/or volume increases to prepare the body for movement. There are parts of our brain that monitor our breathing rhythm, blood CO2, pH, and O2 levels, and will send out signals to either sustain or muffle the stress response based on what it detects. Being stressed will cause you to breathe more. Conversely, breathing more will cause a stress response. Yogis have known this for thousands of years, and have used breathing techniques to influence the state of their nervous system.
It is for this reason that slowing down your breathing is associated with the relaxation response of the body. One of the benefits of nasal breathing is that it increases airway resistance, which naturally slows down our respiration rate. Numerous studies have demonstrated that practicing breathing rates of 6-8 breaths/min leads to higher parasympathetic activity.
When our body is in a relaxed, parasympathetic state, it uses the primary breathing muscles (for inhalation):
diaphragm
intercostals
inside.ucumberlands.edu
When our body is in a stressed, sympathetic state, it uses additional secondary/accessory breathing muscles (for inhalation, non-exhaustive list):
Scalenes
Sternocleido-mastoid
Pectoralis Major/Minor
Serratus Anterior
inside.ucumberlands.edu
In an optimally functioning system, these secondary muscles are used for inhalation when the body needs a substantial increase in airflow. This is appropriate when the cells of the body must generate energy to keep up with physical activity. If you are being chased or playing a sport at high intensity, these muscles will appropriately kick in. As the need for increased airflow reaches high levels, the body will eventually switch to a mouth breathing strategy. This is in response to a short term, high-level stressor.
Modern life is characterized by prolonged, mid-level stressors, as opposed to the more extreme environmental stressors and subsequent relaxation of our distant ancestors. Neanderthal Fred didn’t have to worry about his mortgage or looming project deadlines. He would either kill or be killed by a sabertooth tiger and then eat and rest. We see wild animals behave in this way all the time. Go to the Serengeti and you’ll see a Zebra escaping death from a lion, and minutes later rolling around in the dirt relaxing.
This repeated exposure to mid-level stressors prevents our sympathetic nervous system from ever turning off. Notice how when somebody pisses you off, your breathing rate increases? It doesn’t matter if you are being attacked physically or if Karen said something dismissive; you will have the same type of response in the body.
This can result in the recruitment of these secondary breathing muscles. With prolonged exposure (either by staying in a stressful situation, or thinking about it over and over again), these breathing patterns become our normal.
Mouth breathing utilizes a chest breathing pattern, while the diaphragm moves significantly more with nasal breathing (Trevisan et al. 2015). Remember the 2-way breath-nervous system communication? Chest breathing is connected to the sympathetic nervous system and the use of the secondary breathing muscles. These muscles are also connected to the neck, and their overuse can theoretically lead to forwarding head posture, cervical changes, and possible TMJ dysfunction (yet to be demonstrated in research that I have come across).
Highlights of diaphragmatic breathing:
Improved parasympathetic tone
Enhanced opening of lower lobes of the lungs. Due to gravity and surface area, the lower lobes contain a larger percentage of blood in the lungs than the upper lobes.
This will result in:
Improved gas exchange. Some studies have shown an increase in blood oxygen of 10% (arterial pressure) with nasal breathing vs mouth breathing. Stabilization of lumbar spine. The diaphragm compresses the contents of your abdomen, increasing intra-abdominal pressure around your low back.
Lie on your back. Get comfy. Put your hands around your lowest ribs, with mild pressure. Allow yourself to exhale. Inhale slowly and quietly. Can you feel your sides expanding into your hands? If so, you are breathing with your diaphragm.
A couple of ways to stimulate your diaphragm.
Exhale, don’t inhale until you feel a desire to breathe. This will stimulate your phrenic nerve to activate your diaphragm. This isn’t an exercise in will power, just do it until the first noticeable desire to breathe.
Exhale. Pinch your nose. GENTLY try to inhale 3 short times. Let go and gently inhale in through the nose.
(https://snoringcanada.com/tips-help-stop-sleeping-open-mouth/)
Open-mouth breathing is a risk factor for obstructive sleep apnea and has been correlated with upper airway collapsibility. (Kim et al. 2010)
Sleep is a time for rest and recovery. Mouth breathing dries out the airway and constricts the blood vessels in the lungs. Mouth breathing biases your body towards a sympathetic state, fight, or flight state. Parasympathetic activity (“rest and digest”) is crucial for recovery. As we have discussed in other blog posts, the “fight or flight” the system releases hormones that break down tissues in order to provide fuel for movement. If the body is stuck in this state due to chronic stress and breathing dysfunction, it won’t effectively rebuild tissue from all of the HIIT workouts you are doing. Since a large portion of this recovery process happens while you sleep, it is especially important to breathe in a way that shifts your nervous system state into “rest and digest” mode. This is why nasal breathing is so important for recovery!
(https://www.instituteforchronicpain.org/treating-common-pain/what-is-pain-management/therapeutic-neuroscience-education)
We have previously discussed pain as an alarm system. The more stressed the body is, the more easily pain is triggered, and the more intense it will be. By breathing in a way that decreases stress, we can feel pain less often, and at a lower intensity. Nasal breathing can help with this!
The body creates nitric oxide in the paranasal sinuses. Nitric oxide opens your blood vessels lowers blood pressure and is a natural anti-viral and anti-bacterial chemical. This is one of the reasons breathing through the nose sterilizes air as it enters your body.
Want to increase nitric oxide release in your nasal cavity? Hum on an ‘m’ or ‘n’ sound for a few minutes. Nitric Oxide levels in the nose have been measured at up to a 15 fold increase in the first few minutes of doing this (Weitzberg and Lundberg 2002). It seems that the vibrations knock more of the molecules off of the sinus cavity walls, like shaking leaves from a tree. Humming is also great for stimulating the vagus nerve, which runs alongside your vocal cords. The vagus nerve stimulates the parasympathetic nervous system and puts the brakes on the “fight or flight” response. This is why some groups of monks will chant for hours a day!
It is hard to breathe through your nose if it is blocked! Try this exercise recommended by the Buteyko Clinic. It contributes to the build-up of CO2 in the blood, and subsequently in the nasal cavities. This dilates your blood vessels, as well as your airway and nasal passages (Casale et al. 2008).
Another idea is to try humming. In this case study, one person’s chronic sinusitis was nearly eliminated from 4 days of 1-hour humming sessions.
Once cleared, ventilation of the sinuses through nasal breathing is important to maintain a passageway that air can flow through. In other words, breathing through your nose will become easier the more you do it (Weitzberg).
Occasionally the source of nasal congestion is due to polyps, a severely deviated septum, or some other structural blockage. Exercises can still help, but other treatments may be necessary under these circumstances.
___________________________________________________________________
As you can see, there are many good reasons to breathe through your nose, and solid evidence to support most of them. It may feel awkward at first, but stick with it and you will reap the benefits!
#PT/MOVESTRONG/blogs