Do you breathe through your nose all the time or just some of the time or maybe rarely? Do you even know? Since breathing is an automatic process most of us don’t notice how we do it. Even when we are out of breath what we notice is that we are breathing hard more than how we are breathing. As a human being we are designed, if designed is the right word, to breathe through our nose; that’s what it is there for. It’s not just decoration. There are lots of things about our noses which give us good reasons to breathe through our noses in preference to breathing though our mouths.
Your nose is part of your respiratory system and as such is the entry to it. The next part of the respiratory system is the nasal cavities (sinuses) which the air you breath in pass through relatively slowly, due to the complex structure, compared to breathing through your mouth. This enables the air to be warmed by the blood vessels and capillaries in the nasal cavities, moistened by the mucous secreted there and cleaned up from pollutants such as dust, pollen and germs which are filtered out by the nasal hairs and microscopic cilia in the nose. So if you breathe through your nose you get relatively clean, warm and moist air in your lungs compared to what arrives when you breathe through your mouth.
Another important function of breathing through your nose is providing you with nitric oxide (as opposed to nitrous oxide which is what you really don’t want in your airways). Nitric oxide is a really important chemical for your body but its effects on the body and amounts needed are complicated as it’s involved in transmitting messages in many different systems within the body. It is released in the inner layer of all blood vessels allowing them to relax and keeping them flexible enabling them to dilate and increase blood flow, regulate blood pressure and improve brain function. It also has an anti-inflammatory effect which reduces the risk of plaque building up and restricting blood vessels.
Going back to breathing through your nose, nitric oxide is produced in your nasal cavities in relatively high levels and contributes to your first line of defence against microorganisms (it kills bacteria), and the automatic inhalation of nitric oxide as you breathe in is also thought to contribute to improving lung function by stimulating dilation of blood vessels and capillaries. This coupled with the slower movement of air through the nasal passages helps you breathe more efficiently as it keeps the oxygenated air that you breathed in in the lungs longer allowing more oxygen to be exchanged for carbon dioxide in the blood stream and hence more carbon dioxide to be breathed out. It might not feel like this as you try to get used to always breathing through your nose, particularly when you’re exercising but over time your breathing will become more efficient. It won’t happen overnight; you need perseverance! Those days when you don’t feel like exercising hard are ideal for a low intensity day practising nasal breathing, maybe by starting with a fast walk. When you’re breathing hard, daft as it sounds it helps recovery if you hold your breath for a few seconds before breathing out!
Breathing through your mouth is for extreme occasions when you really need to get more air in quickly but if you perfect your nasal breathing those extreme situations will arise less often and just for good measure all that extra blood flow to the capillaries will increase your endurance. You can feel good about having a regular lazy exercise day with all the benefits you get from teaching yourself to breath well through you nose all the time! Oh and I would definitely recommend practicing somewhere vehicle free – exhaust fumes are really smelly.