So why should we breathe through our nose when we run?

I was out with a group of really old, close friends on Friday night and when the conversation turned to running we got chatting about breathing. I begun to ask them how they breathed when they ran, neither of them where sure and I suggested that they begin to try nasal breathing running. To which, they both reasonably asked, “Why should we breathe through our noses when we run?” A great question and one that we then chatted about.

One thing that goes through my head whenever answering this question is just how technical / scientific to get. Simple is best, but no information about the impact really isn’t helpful, so that provides a good challenge for me in structuring the answer. I’ve settled on the best way of answering this is to start at the nose vs mouth and then follow the path the air takes as it travels down into the lungs, hopefully into the blood and then back out through the nose.

Another reason this seemed a good topic to broach here now, is the changing of the seasons and the dropping temperature of the air.

So why should we breathe through our nose when we run?

Firstly, when I answered the question it was all centred around running easy, at a conversational pace and nothing faster than that (which the majority of running generally happens at).

1. Our nose was made to breathe and smell. It’s an incredible device that is perfect for breathing. Using our nose we warm, clean and humidify the air. Versus our mouth, this just doesn’t happen. With winter coming this is so much better. Using your mouth to take a gulp of cold winter air and our throat get’s irritated, dries out, making breathing harder and far more uncomfortable. As opposed to our nose, which takes that air in, warms & moistens the air before letting it drop down into your lungs. Throat soothed we can breathe easier.
2. If we breathe in anything less pleasant (pollution, etc) the nose will clean and redirect this into our stomach, to be coughed up and got out of our body. Yes a little disgusting, but better that, than dropped into our lungs and causing issues there.
3. When we breathe using our nose – we make better use of our diaphragm. Imagine our core is a giant cylinder. The diaphragm acts as a piston, dropping down on the inhale, pulling all that wonderful oxygen into our lungs. The best place to get oxygen into our lungs is the base, where the lungs are at their largest and has the greatest amount of our air sacs, waiting for blood to pass through and collect oxygen. The best way to do this, use the diaphragm. The best way to use the diaphragm, breathe through your nose.
4. Alternatively use your mouth to breathe, try breathing through the mouth and compare to the nose. Put one hand on your chest and one on your stomach. Feel what the difference is like. With the mouth, it can be harder to use the diaphragm in the same way, you may find yourself using the upper chest and neck accessory muscles to try and force the rib cage up and out, pulling air into the lungs. The air just won’t travel as deeply into the lungs, it is less efficient. One thing that lots of people aren’t so aware of is just how much air is lost to “dead space”, effectively it is breathed in, fails to reach the air sacs in the lungs and gets breathed back out without being of any use at all. When we breathe in, air has to travel down the throat and into the lungs. This is where, on easy running, the mouth breath falls down massively in comparison to the nose breath. You may struggle to get as much air, to the same depth, using the mouth over the nose. The result, less effective breathing through the mouth, overusing upper chest muscles & neck muscles to pull this air in and a need to over breathe to get oxygen in and carbon dioxide out.
5. The nose is lined with all these tiny little hairs, and is a smaller space than the mouth. As a result the resistance to breathe is harder. So initially this does feel like harder work. The solution – slow down and adapt. Over time (for me this took around a year) you can run for longer nasal breathing – however far more efficiently. Running against this resistance enables you to harness the benefits of clean, warmed air, being pulled in via diaphragmatic breathing to the base of your lungs. Your upper body is relaxed, your meeting your bodies needs without overly stressing areas that should be relaxed. More relaxed = better running form, less likelihood of injury, calming mindset and far better overall performance.
6. Another wonderful trick our nose does is release a gas called Nitric Oxide into our sinuses. The beauty of this little gas is two fold. Firstly it acts as a vasodilator, helping the airways relax for the air as it drops into our lungs. Secondly it helps the air distribute more effectively when it reaches the lungs. The lungs are full of air sacs, whilst the most are at the base they are throughout the lungs. The more air sacs you can get air into, the better opportunity of blood to pass through and receive the oxygen. Mouth breathing – no nitric oxide to help with distributing the air throughout the lungs.
7. As we learn to nasally breathe, our breathing slows, becomes more relaxed and this lets the magic in the blood vessels happen. What we are all after is getting the oxygen out of the blood and into the muscles (which are doing all the work running). The longer we take a breath, the more carbon dioxide builds up in the blood. Our blood releases the oxygen in the presence of carbon dioxide, to be taken back to the lungs and breathed out. The longer we take to breathe out, the more time we are letting the body swap carbon dioxide for oxygen, before we need to then release. Getting used to slightly slower nasal breathing improves this blood / oxygen exchange, which in turn keeps out muscles better supplied with oxygen and more able to carry on running.
8. I love this next one. Nasal breathing uses our diaphragm, the more we use our diaphragm, like any muscle the stronger it becomes. The stronger it becomes, the better it works and the better we work. Our diaphragm has 3 main functions. To pull air into our lungs, to stabilise our core and to move our lower organs which helps with digestion. Nasal breathing when running really gets the diaphragm working. So thinking about these 3 benefits you are helping your body so much. I’ve gone through how we improve pulling air into the lungs. The second benefit – stability is so valuable for runners. As I mentioned above our core is like a cylinder, with the diaphragm pulling down, creating pressure to stabilise ourselves to allow us to move. The more stable our core, the better we can move. Without using our diaphragm effectively we can never be as stable. The best way to use your diaphragm, breathe through your nose. The third one is how it helps us digest our food (who knew – nasal breathing and running helps our digestion). As the diaphragm descends on an inhale, it pushes the lower abdomen out, including our internal organs, massaging them and helping everything move along. Healthier digestion, healthier body.

It’s such a simple thing, which is hard to begin doing, but with practice is so beneficial. With winter coming, bring cold air it’s a great time to start the practise.