Often you see fighters get fatigued as a fight wears on and they begin trying to take in more air by opening their mouths. Although this feels like the right solution, they are actually doing themselves more harm than good and exposing themselves to greater potential for injury in the process. It may feel like an easy way to get more air, but there are greater benefits to be gained by simply shutting your mouth and taking a deep breath...through your nose.
Breathing through your nose, instead of your mouth, has numerous benefits. First off, it helps control your breathing and provides for a more even flow of air, in and out of your lungs. More controlled breathing will help you relax and prevents your brain from setting off any alarm bells that might interfere with your body’s natural ability to cope with stress and pressure.
Breathing through your nose also helps maintain the proper balance of oxygen and carbon dioxide in your blood. As opposed to your one, big mouth, your nose provides a smaller entrance (or two to be exact) for inhaling and exhaling. The smaller passageways slow the escape of air. When the air isn't able to exit as quickly, this gives your lungs more time to pull the oxygen from it and put more of it to use. This natural regulation of airflow encourages the proper balance of oxygen-carbon dioxide exchange and better overall oxygen absorption.
The response to the amount of air you're taking in doesn't only affect your body, but your brain also gets in on the action. When you exhale through your mouth, your brain thinks that carbon dioxide is being lost too quickly, so it slows down the flow of oxygen and the blood vessels constrict. In order to make up for the lost oxygen and overcome the restricted blood flow, you have to breathe harder and more often. Breathing through your nose allows you to remain calm, controlled and effortless in your breathing.
Breathing through your mouth also exposes you to more pollutants in the gym and let’s face it, your typical boxing gym is not the cleanest environment in the first place. Your nostrils and sinuses, on the other hand, can serve as a germ filter. When you breathe through your nose, it warms the air being taken into your lungs and produces nitric oxide that helps kill incoming pollutants. When you are training for a fight, the last thing you want to get out of the gym is a bug of some sort. Breathing through your nose will help cut down on the chance of that happening.
Other benefits of breathing through your nose are that it has also been shown to help regulate your body temperature and can even affect your sleeping patterns. Both affect your general health and well-being as a fighter.
All that being said, breathing through your nose can obviously improve your cardiovascular endurance, but it also decreases your chance of sustaining a broken jaw. Numerous fighters have gotten injured from getting hit while their mouths hung open, gasping for air. It's better and more effective to bite down firmly on your mouthpiece and take deep breathes through your nose, in training and during a fight.
By breathing through your nose in the first place, it keeps you from letting your opponent see that you are visibly winded. It's much more intimidating for your opponent to look at you standing in front of them with your nostrils flaring, rather than your mouth hanging open from exhaustion.
Its one thing to go through life, not fully understanding how every part of your body can work for or against you, depending on how you use it. But, as a fighter, whose entire body is involved in a risk or reward proposition every time you enter the ring, nothing can be taken for granted. Maybe up until now, you hadn't given it much thought, but your nose has a primary purpose and now you can breathe easy knowing what that is.