The Importance of Nose Breathing & the Problem with Mouth Breathing During Aerobic Exercise

When we refer to aerobic exercise, we refer to brisk walking, jogging, running, bicycling, dancing, and other physical exercises that cause a marked, but temporary, increase in respiration and heart rate. Many people doing aerobic exercise either breathe through their mouths the entire time or do so when they feel they need more air. Habitual mouth breathing is not a good idea, for reasons you will learn about below. So here is the first tip:

Inhale and Exhale Mainly through Your Nose: Whether you are doing aerobic exercises or not, it is best, if possible, to inhale and exhale through your nose as much as possible. Or, if you need to have a longer exhalation than is possible through your nose, you can exhale through pursed lips (as though you were blowing gently on something).

Why is it so important to inhale through your nose? There are several reasons for this. When we inhale through our nose, the hairs that line our nostrils filter out particles of dust and dirt that can be injurious to our lungs. If too many particles accumulate on the membranes of the nose, we automatically secret mucus to trap them or sneeze to expel them. The mucous membranes of our septum, which divides the nose into two cavities, further prepare the air for our lungs by warming and humidifying it. Over time, this filtering and humidification process helps protect our lungs from the damage that would otherwise occur.

Another very important reason for breathing through your nose--one that very few people are aware of--has to do with maintaining the correct balance of oxygen and carbon dioxide in your blood. When we breathe through our mouth we usually inhale and exhale air quickly in large volumes. Mouth breathing often leads to a kind of hyperventilation (breathing excessively fast for the actual conditions in which we find ourselves). It is important to recognize that it is the amount of carbon dioxide in our blood that generally regulates our breathing. Research has shown that if we release carbon dioxide too quickly, the arteries and vessels carrying blood to our cells constrict and the oxygen in our blood is unable to reach the cells in sufficient quantity. This includes the carotid arteries which carry blood (and oxygen) to the brain. The lack of sufficient oxygen going to the cells of the brain can turn on our sympathetic nervous system, our "fight or flight" response, and make us tense, anxious, irritable, and depressed. There are some researchers who believe that mouth breathing and the associated hyperventilation that it brings about can result in asthma, high blood pressure, heart disease, and many other medical problems. Some people, for instance, get exercise-induced asthma, a temporary condition in which one begins gasping for air. (These factors are discussed in more depth in The Tao of Natural Breathing, the three-CD set Natural Breathing, and Free Your Breath, Free Your Life.

Here is our second tip: 

Don't Let Yourself Become Breathless: When you work out aerobically, of course, the whole point is to find ways to get more health and fitness benefits from your workout. Here are some questions you might ask yourself. Would you like to burn more fat during your fitness workout? Would you like to reduce exercise-related fatigue and injury? Would you like to increase your endurance and stamina? Would you like your workout to help improve your breathing? If your answer is "yes" to any or all of these questions, and it no doubt is, then there is one simple thing you can do: don't let yourself become "breathless" at any point during your workout. When you become breathless, you undermine your breathing coordination, burn sugar instead of fat for fuel, become tight and tense (which can promote injury), and, in general, undermine your endurance and stamina. Habitual mouth breathing can lead to a sense of breathlessness.

The simplest way to know whether you are exercising too intensely and becoming breathless is to try to speak several sentences out loud while you're working out. If you can't do it without gasping for air, then your workout is no longer "aerobic"--it is, or is about to become, "anaerobic," which means that it is proceeding without oxygen and you are no longer burning fat for fuel. Another way to look at what has happened is that you are hyperventilating, which means that you won't get oxygen where it needed in your brain and body and you will feel as though you are out of breath, even though you may have plenty of oxygen in your blood.

A simple way to ensure that you are working out at a level that will not make you breathless is to inhale and exhale only through your nose. If you try this you will quickly discover, especially at the beginning, that you will have to work at a slower or less-intense rate during your workout. Gradually, however, your breathing coordination and blood chemistry will improve and you will be able to do more and progress more rapidly, eventually going well beyond your previous limits. You can also, if you wish, breathe out slowly through pursed lips, as I already mentioned.

Another way is to use your pulse rate as a guide. In his book The Portable Personal Trainer, Eric Harr suggests that we subtract our age from 180 to determine the upper limit of our pulse rate during exercise. The key is to stay below this number. He also suggests that we use a "heart-rate monitor" to ensure that we don't go above this number. He does point out, however, that because of individual differences this number may not be accurate. So you will need to fine-tune your aerobic routine and your breathing to take into account your own situation.

When you become breathless, you are in the same situation, though only temporarily, as someone who has emphysema. In this situation, the diaphragm hardly moves at all and one tries to breathe by raising one's shoulders (which takes weight off the top of the lungs and stimulates shallow breathing) and using one's chest muscles, which is a very inefficient way to breathe, since the diaphragm is the main and most efficient breathing muscle.

By the way, if you would like to read an interesting, informative article on breathing for athletes and non-athletes alike, please read the article by Perry Louis Fields, a member of the U.S. Track and Field Team and a member of the USATF (United State Track and Field Federation).

This page is an edited version of an piece available on the Authentic Breathing Resources website, where you can find many more articles on breath and breathing.