Better breathing while running

nasal breathing while running

A question that comes up a lot at workshops is how to breathe better while running. Breathing’s influenced by a lot of different factors, from how stressed you are, through how easily your ribcage and upper back move, to whether you’re pushing the speed faster than your body’s ready for.

In ChiRunning, we recommend breathing through your nose, at least while running at an easy pace. If you’re used to inhaling and exhaling through your mouth, nasal breathing can feel awkward and unnatural at first, and will likely take some practice to get used to. In this post, I’ll talk about why it’s worth the perseverance, a little about what to expect, and how to overcome some of the obstacles.

Why nasal breathing?

Reduced over-breathing

When we feel the need to inhale, it’s not driven by a lack of oxygen in the body. It’s triggered by your brain. As the carbon dioxide in your blood reaches a level that your brain has decided is ‘high enough’, it flicks the switch and activates the breathing reflex. That ‘high enough’ level is based on what your body is used to. So if you have a tendency to breathe heavily, your brain will be less tolerant of rising CO2 levels, and you’ll feel the need to inhale sooner. Puffing and panting tends to lead to more puffing and panting.

By inhaling and exhaling through the nose, whether running or at rest, you’ll tend to breathe more quietly, lightly and easily, and your brain’s ability to handle higher levels of CO2 will increase. For more on the effects of over breathing, check out The Oxygen Advantage by Patrick McKeown.

More efficient delivery of oxygen

Runners are often advised to mouth breathe while running because it gets more oxygen into the body more quickly.

But getting enough O2 into the body isn’t likely to be an issue unless you’re running at altitude. What matters is getting it to your working muscles and all your other cells, where your body can actually use it.

Oxygen is carried around the body by haemoglobin molecules in your red blood cells. To get the oxygen molecules to detach from the haemoglobin and travel into your muscles requires the presence of carbon dioxide. It’s called the Bohr Effect.

When you breathe through your mouth, you can end up exhaling too much CO2, which causes the blood to hold on to the O2 instead of delivering it to where it’s needed. Nose breathing helps prevent CO2 levels from dropping too low.

It’s not a case of more oxygen equals better. More efficient use of O2 is better.

Release of the miracle molecule

Nasal breathing also releases nitric oxide (NO) into your airways and blood stream. NO has been dubbed the ‘miracle molecule’ It’s a vasodilator, which means that it causes the airways in the lungs to expand. It also helps keep your arteries pliant and elastic, and counters the stiffening that can happen over time. Our bodies naturally produce NO from the lining of our blood vessels, but there’s also a reservoir of it in the nasal passages. When we breathe through our noses, it takes the NO down to the lungs where it can do its magic.

Breathe better quality air

And then of course, there’s the obvious. Unlike your mouth, your nose is set up to protect you from invaders, dirt and other nasties. It warms and cleans the air before it makes it down to your lungs.

And better running

Alongside these health benefits, nasal breathing can also have a positive effect on your running.

It keeps you running properly in your aerobic zone. I’m a fan of Matt Fitzgerald’s 80/20 approach to running, where 80% of running is done at an aerobic pace, and 20% is speed work. Many runners train in the muddy middle – too fast to trigger adaptations in the aerobic system, and too slow to efficiently train for speed. Doing all my easy runs with my mouth shut keeps my pace from creeping too high.

And it can also add a bit of challenge to my training as well. Running with nasal breathing at a very easy pace (less than 75% max heart rate) helps to trigger the parasympathetic nervous system and feels very relaxed. At a slightly higher pace or on a hilly course, it becomes harder work to run and keep your mouth closed. So it feels like the equivalent of strength training for my cardiovascular system.

When do I use nasal breathing?

For my very easy zone 1 runs – warms ups, cool downs and recovery runs.

For my long slow distance runs, when I really want to be sure I’m not pushing too hard on the accelerator pedal.

For base Zone 2 runs, when I want to add a little more work to what should be an easy run pace-wise.

And at the start of a race, to keep me relaxed and help stop me going out too fast too early.

How to get started with nose breathing?

Hopefully by now I’ve convinced you that nasal breathing is worth a try.

If you’re interested in giving it a whirl, first check out your breathing when you’re not running. Is it quiet, easy and relaxed? Do you breathe through your nose or your mouth when you’re at rest? When you’re walking?

If you tend to inhale and exhale through your mouth during your normal day-to-day, start by getting used to nose breathing while not running.

Once you’re comfortable with nasal breathing while walking, try introducing it into your warm ups and cool downs. Now for the advance warning: if you’re used to breathing through your mouth when you run, nasal breathing will likely feel a little challenging at first. Just a few of the things that you may experience:

  • A runny nose
  • A feeling of running out of breath at your usual pace
  • Tension in the face and jaw

If you feel as though you’re not able to get enough air in, slow down. Take walking breaks or breathe through your mouth if you need to. Don’t force it. You’re looking to run in a more relaxed way, not add stress.

If you experience facial tension, you may be running at a higher pace than your body’s ready for. You’re looking for your breathing to feel easy, rhythmic and quiet, not forced. This is something that I struggled with when I first started nose breathing, particularly on longer runs. As well as slowing down, I found that focusing on breathing into my lowest ribs, rather than on getting air in through the small hole in my face, allowed me to run without tension.

For the runny nose, there’s not much you can do except take plenty of tissues! This has improved for me over time, but can still be an issue in colder weather.

After a lot of practice, nasal breathing’s become just part of how I run. Running at a slow pace with my mouth open feels a bit wrong.

I find that with nose breathing, I recover more quickly from longer runs and they don’t take as much out of me. And when I do mouth breathe, for example while racing or doing speed intervals, I’m more easily able to find a relaxed breath.

That all being said, I don’t run every easy run with my mouth shut. Sometimes it’s nice to be ‘let off the leash’ and just run with no constraints. Running should be fun, after all ☺


  1. It’s interesting to revisit nose breathing, sometime ago I trained myself to do this, it took a while but once I got it I found that I was actually able to run faster and further and if I tried to breathe through my mouth I felt as though I was suffocating. Nose breathing really deepens your breathing and it’s something I’ve been meaning to return to.

  2. 95% of joggers in the park breathe through their mouth and don’t take advantage of the wonderful functions of the nose. In other words drying their airways AND letting in polluted air.

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