I hiked a volcano with my mouth closed!
I hiked a volcano a month ago now (time flies) and I managed to breathe through my nose the whole way. Not one sip of air through my mouth, with the exception of some inevitable breaths while chatting. Though I can tell you, the conversation became sparse as we climbed and then quite exuberant as we descended.
So you might be wondering why this is the newsletter topic today.
Well let me start by saying… Most people I saw on that mountain were breathing through their mouths, making an already difficult hike much harder than if they were able to nasal breathe the entire time. That being said, had they all decided that day that they were going to nasal breathe all the way up the mountain, I’d take a guess and say they would have found it quite challenging and the sensation that they weren’t able to get enough air would be strong. I realize this is sounding counterintuitive… it’s easier but harder?! Let me explain.
The reason they would find it hard is that their CO2 tolerance would be lower than someone who breathes through their nose 24/7, including during exercise, and especially someone who has trained with breathing exercises. These things take time and practice. At first, it will be difficult to exert yourself at the level you could with your mouth open. But as your tolerance to CO2 builds, you’ll be able to keep breathing through your nose for longer periods of time while exercising and there are many benefits to this (see below).
With functional breathing exercises and consistent nasal breathing, you train your body to tolerate higher levels of CO2. When your tolerance is low, at the first sign of air hunger or breathlessness, your chemoreceptors trigger a panicked “breathe now” signal, often resulting in gasping and breathing more than necessary, often through the mouth. With practice, you dampen this fear response sensitivity, teaching the amygdala that a little bit of air hunger is safe. On a side note, this is an important reason why this kind of breath training is so effective for anxiety and panic attacks, as hyperventilation and feeling like you can’t breathe is a common symptom and can quickly spiral. When this fear response is conditioned to be less sensitive, this spiral is less likely to occur.
Key training benefits
Back to exercising though, and the other benefits of training to tolerate higher levels of CO2…
There’s a lot but I’m going to keep it to the most “important” ones, in my opinion at least.
Increased oxygen delivery - When mouth breathing, you blow off too much CO2. With nasal breathing, your CO2 levels in the blood remain higher which helps to release oxygen from hemoglobin into your working muscles more readily, improving tissue oxygenation. Your muscles work better with the same exertion. This is known as the Bohr effect.
Nitric Oxide - NO is produced by the epithelial cells that line the paranasal sinuses and you inhale it when breathing through the nose. It is a vasodilator which means it opens up blood vessels to improve circulation and oxygen exchange in the lungs. It’s also a bronchodilator, helping to open up your airways. Extremely key when exercising. There’s even more benefits to NO but I’m gonna leave it at that.
Lower heart rate - since you’re breathing less air with better efficiency, you’re heart doesn’t have to work as hard to pump extra blood to the respiratory muscles, leaving more energy for everything else (your legs running fast for instance.) yay!
Lower perceived exertion & delayed exhaustion - when your tolerance to CO2 is higher, aka your panic trigger is less sensitive, your brain perceives the same exertion as easier because your body feels more in control with your consistent rhythmic nasal breathing. This also allows your need for rapid breathing to be delayed, making you feel exhausted less quickly.
Respiratory muscle strengthening - since nasal passages provide approx 50% more resistance than the mouth, it’s a workout for your respiratory system, making it stronger and more efficient over time.
Accelerated Recovery - nasal breathing triggers the parasympathetic nervous system (rest and digest) so by staying in more of this state while exercising, your body isn’t maxing out your stress hormones during your exertion. This means that your body can shift into recovery mode quickly after finishing.
Overcoming air hunger
So, now can you see why if everyone hiking that volcano was used to nose breathing all the time and continued that in their hike, it would have been better for them?
My challenge for you: Next time you’re exercising, see how long you can go with only nasal breathing before you feel like you need to switch to mouth breathing. Do you notice that the second you start to feel breathless, you automatically switch to mouth breathing?
My suggestion: when the air hunger feels strong and you want to switch to mouth breathing, instead, take a little break and continue slowly breathing through your nose. When your breathing feels under control, begin again. As time goes on you’ll be able to breathe through your nose for longer periods of time.
We never want to force nasal breathing so start slow. If nasal breathing during high intensity exercise is too much, even with taking breaths when you feel the urge to mouth breathe, start with low intensity exercise first.