Can we suffer from too much oxygen?
Better training and better recovery through breathing
In part one of this blog, I covered the basic anatomy of breathing and the importance of increasing carbon dioxide in your body to get more oxygenated blood to your tissues, organs, and working muscles. How do we do this? And, how do we do this to improve our workouts and our health?
Nasal breathing vs mouth breathing
We were born as innate nasal breathers.
Mouth breathing activates the upper chest and lungs. Mouth breathing provides no resistance to inhaled or exhaled air. And, we’re able to take in more volume of air faster especially during hard workouts. “Inhaling air through the mouth decreases pressure, which causes the soft tissues in the back of the mouth to become loose and flex inward, creating less overall space and making breathing more difficult.” (Nestor)
Sleeping with mouth closed can improve the quality of your sleep. Dry mouth in the morning means you’re mouth breathing or switching between nasal/mouth breathing. Mouth breathing changes pH levels in the mouth and contributes to demineralized teeth. Sleeping with an open mouth closes off the airways even more and increases snoring and sleep apnea. Mouth breathing can decrease oxygen saturation (SpO2) and causes increased fluid loss through the night.
Many of the problems of mouth breathing can be attributed to other things (allergies, asthma, fatigue, struggling in workouts, etc.), overlooked completely, and happen on a microscopic level over many years.
Nasal breathing gives increased resistance to air movement, but better gas exchange from the lungs to the blood. Nasal breathing increases nitric oxide. (Nitric oxide is a vasodilator; by widening blood vessels, nutrients and oxygen are delivered faster to working muscles.) Nasal breathing encourages deep, lower ribcage, diaphragm breathing. Nasal breathing makes the airways wider, making breathing easier. If you’re currently breathing through your mouth all day long, it’s possible to train your nasal passages and airways to get more toned and be more open allowing more volume of air to flow.
How to increase carbon dioxide
We expose our bodies to more carbon dioxide by focusing on nasal breathing. By slowing down breathing, breathing more through the nose and breathing deep in to your lower ribcage (diaphragm breathing), your body is exposed to more carbon dioxide. At first this can feel uncomfortable, especially if your normal breathing pattern is high, shallow, quick mouth breathing, aka over breathing. The ideal breath cycle at rest is 5-6 inhale/exhales per minute.
We’ve been conditioned to be desensitized to carbon dioxide. A good example during the COVID-19 pandemic is with wearing a mask. You might feel claustrophobic or some ‘air hunger’ – can’t wait to get it off! This is not hypoxia (low oxygen), it’s an increase in carbon dioxide in the blood and an overly sensitive reaction to this gas. The increase in carbon dioxide is causing a better release of oxygen from the red blood cells to the tissues. The answer is to increase your tolerance to higher levels of carbon dioxide. Breath holding exercises will also increase carbon dioxide and decrease sensitivity to this gas.
Think: low, slow and through the nose.
Non exercise breathing
Breathe through your nose as much as possible. Soften and slow your breathing to get used to the increases in carbon dioxide (can cause some tingling and light headedness) and open your nasal airways. Work on 5-6 breath cycles per minute. This will also improve your HRV (heart rate variability). Over breathing (high and fast) causes the alveoli to constrict and restricts oxygen/carbon dioxide exchange between the lungs and blood and out to the cells.
Steady, slow deep breathing, fully engaging your diaphragm for the inhale and exhale, can actually increase your lung capacity – beyond what you do in your workouts. Practicing at rest will also help you recover faster between intervals and after a hard workout. Respiration can lead to restoration.
Breathing during exercise
I’ve always been a fast breathing, mouth breather when it comes to exercise, especially when it gets hard. In fact, many years ago, I was introduced to the concept of breathing through the nose during workouts and I thought “No Way!”. Fast forward and I’m now reexamining my thinking. The fact of the matter is that the evidence is real: nasal breathing and slower, longer exhales can improve your VO2 max and physiological economy in running. Long slow exhales increase carbon dioxide levels, increase oxygen saturation and boost your aerobic endurance.
But, for high intensity intervals, long, slow inhale and exhale does not work. Mouth breathing brings in more volume of air faster to meet your metabolic needs when training hard. But, for low intensity endurance work, you can train yourself to breathe slower and through your nose both improving your fitness and your overall health.
Here are a couple of easy experiments to try. During an aerobic indoor bike workout, breathe slowly in and out of your nose and let your nasal rate of breathing determine your intensity. Go only as hard as you can go and still breathe through your nose. If you’re worried about your oxygen saturation, bring along your fingertip pulse oximeter. Or on an easy run, try counting your breaths: 3 count inhale, 4 count exhale; extend this to 5, 6, 7 count exhale as you progress.
Simple breathing techniques to improve your health and performance
There are a multitude of breathing exercises to help you improve: lung capacity, oxygen utilization, sleep, immune response, tolerance to stress and anxiety, autonomic nervous system balance, decrease snoring and sleep apnea and more.
One of the easiest is one you’re already doing: aerobic exercise. Just try changing up your breathing at rest and on your easy workouts.
Many of the breathing techniques on this list are based on techniques that are decades or centuries old. Many have been modified from their original form to fit into modern life. If you’ve taken a yoga class, you’ve already experienced at least one form of healthy breathing. Most are free. And, you’ve got all the equipment you need with you every day.
Nose unblocking exercise – so you can breathe more through your nose! (This exercise can also be done while walking.)
Wim Hof Method: With this exercise, you will notice an increase in your oxygen saturation and breath holding (how to increase carbon dioxide in your blood), after just a few sessions. It’s powerful. There’s some good research into how this method also helps your immune system work more effectively and teaches you how to be calm under stress.
Buteyko Institute of Breathing and Health: This method involves short breath holds to increase carbon dioxide in the blood and helps with anxiety, nasal congestion, sport performance, allergies, asthma, snoring and sleep apnea.
Pranayama refers to the formal practice of controlling the breath, considered the source of our vital life force. This is what’s commonly used in yoga practice. This alternate nasal breathing technique calms the body and mind and balances the autonomic nervous system (sympathetic and parasympathetic).
Click here to access a one-page resource for several healthy breathing videos (including all mentioned above).
References & Resources
The Bohr Effect
Mark Burhenne, Mark. The 8-Hour sleep paradox: How we are sleeping our way to fatigue, disease and unhappiness. askthedentist.com
Bussotti, Mauricio, et al. “Respiratory disorders in endurance athletes – how much do they really have to endure?”, Open Access Journal of Sports Medicine 2, no. 5 (April 2014):49.
Fingertip Pulse Oximeter
McKeown, Patrick. Oxygen Advantage. HarperCollins Publishers. 2015
Nasal breathing and exercise
Nestor, James. Breath. Penguin Random House. 2020
More on oxygen saturation