The Simple Trick I Use to Nail Zone-2 Pace on My First Run

First run of the training season.

I head out the door, do a few drills to warm up the correct muscles, and get running. It’s base building season, so I know I should stay in zone 2, aka the aerobic zone.

It’s when our muscles use oxygen as their primary fuel source.

Zone 2 is when you’re at 60-70% of your max heart rate, but I don’t need a heart rate monitor to know when I’m there.

I’ve ran enough before that I can tell by how it feels, and I have a trick up my sleeve to make sure I stay there: breathing in and out through my nose, without exception.

This simple trick confidently keeps my heart rate around 135. It did so when I was in the best shape of my life, and it does now when I’m far from it.

The rest of this post is about nasal breathing for runners. I’m fascinated by the power of that simple change, and whole-heartedly believe all runners should practice it.

Here’s why.

Breathing properly

Unfortunately proper breathing is quite uncommon in modern societies. Many of us breath through our mouths, not just when doing high intensity activities, but even when just sitting or walking around.

So what is “proper breathing”, and why does it matter?

Proper breathing is pulling air through your nose with your diaphragm, and letting it out through your nose. You should only involve your mouth when intensity goes towards the extremes.

Just look at all the professional marathoners, Eliud Kipchoge during his sub 2-hour marathon included (cover photo of this post). They all run with their mouths closed.

Breathing properly is foundational to good speaking, running, stretching, strength training, yoga, martial arts, dancing, and pretty much anything and everything you do in life.

And why does it matter? The two primary reasons are oxygen advantage and postural strength.

Let’s dive deeper.

The oxygen advantage

We all breathe for a very simple reason: to get oxygen into our cells.

Oxygen keeps us alive, by “burning” inside every cell we have, thus giving them the energy they need to do their thing.

This cellular process is called aerobic (with oxygen) respiration, and it’s what our muscle cells do when we run at easy, conversational pace. The more oxygen we can provide to our muscles, the better it is for this process.

It might seem that the harder we breathe, the more oxygen we can get to our muscles. But it’s not that simple. There’s a lot of complex processes involved there.

The first thing to understand is air is not oxygen. Thus, whatever oxygen is in air, our body’s need to be able to extract it.

Turns out CO2 is very important for this process. The higher the CO2 levels in our blood, the more oxygen we can get from air. Breathing heavily (like when your breathing through your mouth) flushes that CO2 out of your blood, limiting your ability to use the oxygen from air.

Another important molecule for breathing is NO (nitric oxide), which your body produces in your nasal passages. Like CO2, nitric oxide also improves oxygen exchange in your lungs. And there’s more. Nitric oxide is also a vasodilator, meaning it relaxes your blood vessels and allows better blood flow to your muscles.

Simply put: you get more oxygen into your muscles when you breathe through your nose than you do when you breath through your mouth.

But there’s more.

Postural strength

All of us have two “chains” in our bodies.

The posterior chain, going from the bottom of your toes all the way across your back, wrapping around your skull and attaching to your upper jaw.

The other chain is the anterior chain, starting from your bottom jaw and extending all the way down to the top of your toes.

Your mouth is where these two chains meet.

When you’re breathing through your open mouth, these two chains are unconnected. And that means you have a massive energy leak. You can easily experience this yourself:

Hold your arms out to your sides so they are parallel with the ground. Then ask a friend to push your arms down. If your tongue is relaxed, they can easily push your arms down. As soon as you engage your tongue up against the roof your mouth, you’ll find that you’re much stronger in resisting your friend’s push.

When you breath through your nose when running, you can close your mouth and let your tongue support your head. This connects your anterior and posterior chains into a strong, coherent system.

By closing your moth, you have effectively removed those energy leaks that mouth breathers will always have.

It means every stride you take has more strength to them. It means you can hold up your posture, giving space for your lungs to breathe.

Good posture also reduces wear and tear on your whole body as you run. Less wear and tear means it’s easier to recover and train stronger the next day.

How to become a nose breather?

When you go for your next run, shut your mouth and breathe through your nose.

It’s hard at first, but it gets easier.

As you practice this, your nasal passages get wider. Your body starts producing more nitric oxide.

Slowly but surely, your whole body adapts to breathing through your nose, and you’ll become a better and stronger runner.

Futher reading:

If I managed to pique your interest, I can highly recommend James Nestor’s book, “Breath: The New Science of a Lost Art”.

It’s a a great intro into this fascinating topic.