During periods of intensive anaerobic exercise it feels natural for you to want to breathe through your mouth. After all it makes sense to try and achieve maximum oxygen intake. However, elite long distance runners regularly breathe through their nose during their runs. It is a simple yet effective way to improve their performance and endurance. Nasal breathing has a number of important advantages for runners, such as increased ventilatory efficiency, which means you get more out of each breath, the increased resistance to airflow results in an improved use of your diaphragm and a deeper penetration of oxygen into your lungs [1].
However it extends far beyond running, and you can improve performance, oxygen levels and subsequently cardio during other exercises as well. Athletes such as cyclists basketball players and tennis players, incorporate this too. Professional fighting sports such boxing or mma tend to incorporate nasal breathing as well, which comes with the additional benefit of reducing the risk of a broken jaw if they get punched while trying to catch their breath through their mouth.
Interestingly enough not all sports do this, for example professional swimmers breathe through their mouths, as you get air more quickly, they only have a short amount of time where their head is above the water and mouth breathing accommodates both water and air. But overall, for high endurance sports, nasal breathing has been determined to be the most optimum and efficient way of breathing.
Nasal breathing will feel uncomfortable at first and transitioning from mouth breathing to nasal breathing during exercise may take some time to get used to, it can take weeks or even months. How long will this take for you? Nobody noses. You can try this exercise to help speed up this process. Start by inhaling through your nose, then pinch your nose and hold your breath. Now with your nose pinched, try some light exercise, such as walking up and down the stairs. Release your nose and breathe through your nose again. You should be able to recover in 3 breathes. If not, you’ve hold your breath for too long. Now wait 2 minutes and try this some process again. Repeat for 6 times in total.