Mouth Vs Nose Breathing While Running: A Detailed Comparison

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When you first start running as a beginner, one of the biggest challenges is feeling like you can get enough air when you breathe.

Even the most experienced runners with the most impressive PRs get winded when they try to run too fast.

After all, your heart and muscles need a steady supply of oxygen in order to run, and they need to offload carbon dioxide, and the only way to satisfy those needs is to breathe.

But is it better to breathe through your nose or mouth while running? What’s the difference between nasal breathing and mouth breathing when you run?

In this article, we will discuss mouth vs. nose breathing while running to help answer the ever-important question, “Should you breathe through your nose or mouth while running?”

We will cover: 

  • Why Is Breathing During Running Important?
  • Mouth Breathing vs. Nose Breathing While Running
  • Should I Breathe Through My Nose When Running?
  • How to Start Nose Breathing While Running

Let’s get started!

A close-up of a nose.

Why Is Breathing During Running Important?

It certainly doesn’t take an advanced degree in exercise physiology to know that it’s important to breathe while running or doing any type of exercise, but it’s helpful to briefly cover why breathing during exercise is important and what’s really going on in the body when we breathe.

Breathing is a process that most of us take for granted because we can do it unconsciously, but there’s actually quite a bit going on.

However, in terms of breathing while running, the most important takeaway is that we breathe to take in oxygen and expel carbon dioxide.

Both sides of the circuit are equally important, even though discussions of breathing while running usually focus just on the inhaling (breathing in) oxygen component.

It’s absolutely true that the heart and working muscles need oxygen while you run or perform any kind of exercise, but they also have the critical need to offload carbon dioxide.

A runner outside.

This occurs through exhalation or breathing out.

Carbon dioxide is a metabolic byproduct of producing energy. If too much carbon dioxide builds up in the body, you will die,

At rest, we breathe only a small to moderate percentage of our lung capacity because our need for oxygen isn’t all that high.

This amount of air that we inhale and exhale at rest is known as tidal volume.

However, as soon as we start running, our muscles start requiring a lot of oxygen so that they can produce the energy they need to contract.

Additionally, the energy-generation pathways produce carbon dioxide, which must be removed.

Carbon dioxide is cycled out of the muscles and into the blood, returned to the heart, and then pumped to the lungs, where it is expelled in the air we exhale.

A person nose breathing while running.

Mouth Breathing vs. Nose Breathing While Running

So, what’s better: breathing mouth or nose breathing while running?

For easy jogging, nasal breathing is ideal, but many runners find that breathing through the nose is not sufficient for hard running, especially if they haven’t trained themselves to breathe only through the nose.

Consequently, the answer isn’t as simple as either-or; rather, to best meet your respiratory demands during vigorous running, you may need to breathe through both your nose and mouth.

Some runners have probably heard that they should only breathe in and out through the nose during running without doing any breathing through the mouth.

The nasal passages have filters to warm, humidify, and purify the air you take into your body, helping trap allergens and pathogens before they are absorbed.

Mouth breathing gets a bad rap, but it’s an effective way to increase the amount of oxygen you’re able to take in.

Your mouth can open much wider than your nostrils, and your trachea is much wider than the nasal passages, so the volume of air (and thus oxygen) that can be inspired through the mouth far exceeds that of the nose.

A person holding their chest to breath.

However, although breathing through the mouth during exercise gives you access to a lot more air than the relatively restricted intake of air through nasal breathing, mouth breathing doesn’t permit the same type of filtering, humidifying, and temperature regulating that nasal breathing affords.

As a result, the air you inhale through the mouth doesn’t get the same special treatment, so it’s colder, drier, and may contain environmental allergens or irritants.

Consequently, when air inhaled through the mouth hits the bronchi, which are your main respiratory passages, it can cause exercise-induced bronchoconstriction, or EIB, and/or an asthmatic response.

Symptoms of EIB can include shortness of breath, coughing, chest tightness, sore throat, and decreased endurance.

These symptoms usually appear within a few minutes after you start running and continue either intermittently or consistently until shortly after your workout is over.

Difficulty with mouth breathing is usually exacerbated when running in cold, dry air or when breathing really hard.

In the first scenario, the dry, cold air bypasses the very necessary warming and humidification steps and presents a greater shock to your system than when inhaling on a warm and humid day where the air is already closer to what the bronchi prefer.

This is why it’s particularly common to experience a dry cough when running in the cold.

Secondly, breathing hard through the mouth floods the bronchi with a larger bolus of cold, dry air, so it can overwhelm the passageways and cause irritation.

Interestingly, it is mostly during hard workouts that most people resort to breathing through the mouth as a means to get in as much oxygen as possible.

A person covering their mouth.

Should I Breathe Through My Nose When Running?

Although mouth breathing while running is second nature to most runners these days, there’s anthropological evidence to suggest that humans used to rely predominantly on nasal breathing when running to hunt, travel from place to place, or escape danger. 

Moreover, the impressive Tarahumara (Rarámuri tribe) runners in Copper Canyon, Mexico, who were popularized by Christopher McDougall’s book Born to Run, practice not only the ancient tradition of running barefoot but also the apparent ancient tradition of nasal breathing.

Despite the fact that nose breathing while running seemed to historically meet our oxygen needs, as with most things, somewhere along the way, humans decided that the “more is better” attitude should pertain to our oxygen needs as well.

In other words, if oxygen is necessary for running, more oxygen will allow us to run even better.

A person hunched over from running.

Taken a step further, if we can get a small but sufficient amount of oxygen through the nose but can get a lot more oxygen breathing through the mouth and nose together, we should do the latter because we will be able to run even better.

From this thinking, coaches and exercise physiologists started recommending oronasal breathing (mouth and nose together) to fully maximize the amount of oxygen you can inhale while running.

However, as mentioned, the heavy reliance on mouth breathing while running can create a new problem—exercise-induced bronchoconstriction.

The good news is that recent research into breathing techniques while running found that when runners take the time to adapt to nose breathing while running or doing any type of endurance exercise, they can perform just as well at maximum (anaerobic) efforts than when breathing through the mouth and nose together.

Furthermore, nasal breathing while running at submaximal, steady-state aerobic efforts actually improves running economy because it reduces the oxygen cost of running at a given pace.

This can potentially allow you to run further and longer without fatigue.

Therefore, although the natural hunch is that breathing through the mouth will give you a performance boost because you’re able to get more oxygen, there actually may be performance benefits associated with nasal breathing, especially for endurance athletes.

A close-up of a runner's face.

How to Start Nose Breathing While Running

Unless you are consciously practicing breathing exclusively through your nose while running, there’s a good chance you’re doing oronasal breathing, which again involves breathing through your mouth and nose together.

Even though you’re probably not thinking twice about how you breathe while you run and have concerns that it won’t be possible to change something that’s so unconscious, it is absolutely possible to change how you breathe while running.

The key to changing how you breathe while you run is adopting an attitude of patience.

Most researchers and exercise physiologists note that adaptations in your breathing patterns and mechanics while running take time—typically six weeks to six months.

Factors that impact whether you fall closer to that six-week or six-month mark include things like how long it will take to adapt depending on your level of sensitivity to CO2, how diligently and consistently you work on nasal breathing, how much you run, how long you’ve been running, and how fast or hard you run.

A person breathing with their eyes closed.

In terms of the most effective way to actually shift your breathing mechanics is to slow your pace down all the way until it becomes comfortable to breathe through the nose.

Once you hit a steady-state pace where you can maintain the effort while breathing through the nose, hold the pace. 

Since this will be a slower pace than your usual training speed, you can do part of every run, like your warm-up and cool-down, at this effort.

Then, the next step is to start increasing your pace until the point at which you feel air hunger—the urge to take a huge breath. 

Hover just above this threshold, much like you do with your lactate threshold on tempo runs, for as long as possible. This will desensitize your body to the sensations.

Over time, you can keep pushing this threshold higher and higher.

A runner smiling.

Although it’s most efficient to try and knock out your transition to nasal breathing all at once by trying to practice it every day you run, instead, depending on your training schedule and goals, you might have to play more of the long game and do some nose breathing while running every day but also stick with your mouth breathing for hard workouts.

Other tips to help transition from mouthed breathing to nose breathing while running include the following:

  • Lightly taping the mouth shut or holding small sips of water in your mouth, either of which will naturally cue your body to keep your lips sealed.
  • Wearing nasal strips and internal nasal dilators.
  • Using a neti pot or saline spray daily to rinse debris and mucus from your nasal passages. 
  • Practicing alternate nasal breathing and mouth breathing when you are not running.
  • Warming up before every run so that you can begin with nasal breathing and then ease into faster paces.

With patience and practice, you can train your body to get all the oxygen you need by breathing only through your nose while running.

Interested to know your breathing volume capacity? Check out our Bolt test!

A runner hunched over, hands on knees.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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