Our somewhat surprising breathing patterns during sleep

We spend 1/3 of our life sleeping. And sleep is arguably one of the most important aspects of good health. Therefore, I expected that during sleep, breathing would be slow, deep, and rhythmic (i.e., “perfect”).

However, a review published in 1984 in Clinical Science showed that breathing rate is actually highly variable during sleep. In fact, breathing rates often increase and become irregular and shallow, especially during rapid eye movement (REM) sleep.

Although breathing rate might increase, the overall breathing volume is reduced, dropping as much as 16% from waking values.

This drop in volume is accompanied by relative hypoxia (low O2) and hypercapnia (high CO2). We discuss improving CO2 tolerance quite often. During sleep, your CO2 tolerance increases by as much as 66%.

What do these findings mean from a practical perspective?

Well, sleep is clearly a time when breathing should reduce and CO2 should increase. Therefore, if you are sleeping with your mouth open, you are likely overbreathing and not reaching the physiological states your body was meant to reach during sleep.

Luckily, this is an easy fix. Simply taping your mouth at night will restore nasal breathing and will provide the first step in reducing breathing volumes to their natural levels during sleep.

If you are not already, give it a shot. This one small change has had the greatest positive impact on my health and energy. It might do the same for you.

In good breath,
Nick

Breathing Actually Reduces Oxygen (by 97%)

You’ve probably heard some variation of this by now: You can go weeks without eating, days without water, but only minutes with breathing.

But, have you stopped to think about what that really means?

I think we’d all agree that what we drink affects more than just hydration. (For example, weight loss and exercise performance.)

The same goes for eating. You would likely agree that what you eat is important to many aspects of health. For example, sleep and energy levels can be directly impacted by food.

However, when it comes to breathing, this is often overlooked. Most people think breathing is just about getting oxygen. But what if breathing actually limits oxygen?

Breathing: Is it Really About Oxygen?

Almost all “breathing techniques” are centered on oxygen. This makes sense. Oxygen is, after all, our #1 source of energy.

But what happens if we shift our perspective and look at breathing and circulation differently?

In the atmosphere, oxygen exerts a pressure of ~160 mmHg. In our cells, it exerts a pressure of ~5 mm Hg. From the time we inhale to the time the air reaches our cells, the oxygen pressure is reduced by 97%.

Therefore, our intricate oxygen transport system can be viewed as a way to limit the amount of oxygen getting to our cells. [1] Meaning, you can’t breathe more and “super-oxygenate” your body.

(Actually, breathing less is the only way to increase oxygen to your cells. But that only corrects under-oxygenation, it does not “super-oxygenate”.)

Breathing Goes Beyond Oxygen

I don’t think we’ll ever understand all of the functions of breathing. But, just like eating and drinking, breathing has impacts far beyond the obvious. Here are a few other reasons we breathe:

• Circulate nitric oxide

• Improve sleep

• Improve cardiovascular health

• Improve autonomic balance

• Improve digestion

• Increase energy levels (well, this is related to O2)

• Synchronize brainwave oscillations

• Improve cognitive function

• Improve emotional control

• Reduce stress and anxiety (or create it, depending on how you breathe)

That’s A Long List

And it should probably be longer.

But here’s the point: Breathing is Fundamental. It’s more important than what you eat, what you drink, or even how you sleep.

But you can’t just ignore these things either. In fact, I believe breathing should support you in your quest to optimize them. Health and well-being are not about any one thing. But, you have to start somewhere. So why not with your body’s most important function?

In good breath,
Nick

[1] This idea came from the great book “Oxygen” by Nick Lane. If you’re a super nerd, I highly recommend it.

Nasal breathing synchronizes brain wave activity and improves cognitive function

Last week, we discussed century-old ideas about nasal breathing and mental function. I said that current science is beginning to catch up. Here’s how.

Modern Science Supports 100 Year-Old Observations

A study published in 2016 in The Journal of Neuroscience showed that nasal breathing is intimately connected to brainwave oscillations, emotional recognition, and memory retrieval.

Intracranial EEG measurements showed that nasal breathing synchronizes brainwave oscillations in the olfactory bulb, the hippocampus, and the amygdala. When breathing was switched to the mouth, this coherence disappeared.

In a follow-on experiment, they showed participants pictures of faces expressing fear or surprise. They had to pick which one it was as fast as they could.

Not only did the nasal breathers outperform the mouth breathers, but they also found that responses were quickest during inhalation versus exhalation. The participants also had more accurate memory retrieval during nasal inhalation.

Taken together, their results indicate that nasal breathing acts to organize brainwave oscillations and improve cognitive functioning.

These results also help explain Guye’s theory about nasal breathing and mental function. That is, they support the quote “Shut your mouth and save your brain.”

Breathing is More Than Just Gases

These results imply that breathing is about more than just about gases. Breathing acts to synchronize brain activity and enhance cognitive function…but only when performed through the nose.

In good breath,
Nick

100 years of nasal breathing and mental function

Happy Sunday! I hope you all enjoyed the extra hour of sleep as much as I did.

Last week, we learned that the nose might provide the link between slow breathing and improved emotional outcomes. Before we explore the modern science behind that idea, let’s go back a century and see what we can learn.

An odd sounding word

Over 100 years ago (1889 to be exact), an author named Guye coined the term “aprosexia.” Although it doesn’t exactly roll off the tongue, it’s pretty great:

• Aprosexia
  : The inability to focus your attention due to nasal obstructions.

Guye argued that headaches and the inability to perform difficult mental functions are both caused by mouth breathing. He even suggested that medical practitioners ensure that breathing was not “habitually or temporarily suspended by breathing through the mouth.” (That advice holds true today.)

Guye put particular emphasis on children feeling “over-pressured” in school. He believed that kids would not feel overwhelmed if they had normal nasal respiration. Finally, he concluded with the quote above.

Old becomes new

There is often hidden wisdom rooted in old observations. And the science is catching up. A new study of the brain suggests that nasal breathing is intimately connected to emotional control. We’ll explore that research next week.

Until then, let’s focus on breathing through our nose 24/7, especially during sleep. Because, as we have learned, that motto was updated in 1983 to reflect the importance of nasal breathing during rest:

While asleep, shut your mouth to save your brain.

In good breath,
Nick

How slow breathing improves emotional well-being (hint: it might be in your nose)

Hi everyone,

I hope you’re having a great weekend.

Let’s continue on our theme of slow breathing and enhanced well-being. If you missed/forgot last week’s post, check it out here.

The paper I’m sharing this week might win best title award (well, at least the part before the colon):

How breath-control can change your life: A systematic review on psycho-physiological correlates of slow breathing

(Click Here to read full summary)

That’s pretty awesome for a peer-reviewed journal article.

This paper examined a wide range of studies to understand how physiological changes associated with slow breathing correlated with improved emotional outcomes.

Here are the common results they found throughout the literature:

• Slow breathing increases heart rate variability

• Slow breathing increases respiratory sinus arrhythmia

• Slow breathing increases alpha brain wave activity

These benefits were correlated with improvements in stress, anxiety, depression, and well-being.

Thus, breathing changes your physiology, and your physiology changes your emotions.

And to me, that wasn’t the best part. This was.

The authors hypothesize that the nose provides the link between slow breathing, brain and autonomic functioning, and positive emotional outcomes. It’s not just slow breathing, it’s nose breathing. Breathing slowly through the mouth would not improve stress and anxiety.

From a practical perspective, all of the studies used breathing rates of 3-6 breaths/min. With practice, we can use an app (such as Breathing Zone) to achieve these slow rates.

However, let’s not rely purely on the science. Try practicing slow breathing at 6 breaths/min for 5 min/day to see the results for yourself. They might turn out to be the most important 5 minutes of your day.

In good breath,
Nick

P.S. Lean into stress.

Breathe profoundly to reduce stress and anxiety

Hi all,

Last week we learned some devastating statistics. (Do you remember that 1 in 3 adolescents meets the criteria for anxiety?)

The study I’m sharing this week shows you how to breathe (hint: deeply) to reduce anxiety.

The effectiveness of diaphragmatic breathing relaxation training for reducing anxiety
(Click here to read on website)

First, a quick rant. “Deep” breathing is not “big” breathing. Often, when someone says “take a deep breath,” we automatically take a big breath.

But, a deep breath simply brings air into the lower lungs (“right before the bottom”) where the largest concentration of blood is due to gravity. It doesn’t have to be (and usually shouldn’t be) big. Maybe we should call in “Profound Breathing”?

OK, rant complete.

In this study, patients with mild-to-moderate anxiety were given instructions on diaphragmatic breathing. They were told to take 10 diaphragmatic breaths, twice daily, which doesn’t sound like too much to ask. They performed this over an 8 week period.

The results showed that diaphragmatic breathing significantly reduced anxiety when assessed on the Beck Anxiety Inventory (BAI) scale. Their average scores dropped from ~19 down to ~5 (lower is better).

The participants also improved physiological indicators of stress, including reducing their heart rate, breathing rate, and skin conductance.

Like I said last week, this isn’t woo-woo pseudoscience. Correct breathing changes your physiology to reduce stress and anxiety.

And the best part is that you can use deep breathing anytime you (or your clients or friends) feel stressed. And you can know that you are changing your physiology to promote relaxation.

In good breath,
Nick

P.S. Did you check out HHPF last week?

How to reduce anxiety and prevent disease

“Anxiety is often excitement and anticipation without the breath.”
- Michael Port

Hi all,

It seems like everywhere we look stress and anxiety are on the rise.

For example, did you know that 1 in 3 adolescents meet the criteria for anxiety in the United States? Or that 14% of active duty military report anxiety?

Not only are these stats devastating in general, but they also have negative implications for long-term health and well-being.

Let’s look at the numbers:

• Anxiety increases the incidence of cardiovascular disease by 52%.

• Stress-related conditions increase risk of autoimmune disease by 36%.

Thus, anxiety isn’t just bad in the moment, it also subjects you to chronic illness.

This is where breathing can help. Slow, deep breathing improves both subjective (e.g., questionnaires) and physiological (e.g., heart rate variability, parasympathetic activity, brain wave activity) indicators of anxiety, stress, and depression.

That last part is critical.

This isn’t some woo-woo, “just take a deep breath” stuff. Correct breathing changes your physiology to promote relaxation and focus. This reduces anxiety and improves your ability to deal with stress. All of which reduces your risk of disease.

Of course, breathing won’t fix everything. But, with essentially no side effects, it seems like slow breathing should be the first place we turn in the treatment of stress and anxiety.

In good breath,
Nick

P.S. If you haven’t heard of the Health & Human Performance Foundation (HHPF), you should check them out. They are a nonprofit organization conducting scientific research on the effectiveness of breathing for stress and anxiety. Click here to learn more about HHPF.

Staying healthy on vacations and “party weekends”

“You should sit in meditation for twenty minutes every day – unless you’re too busy; then you should sit for an hour.” – Zen Proverb

Hi everyone,

I am a pretty structured person. I go to bed at 8 PM and wake up at 4 AM, even on the weekends. And I am consistent with my breathing routine:

• Principle 1: 15 minutes right after waking*

• Principle 3: ~10 minutes, right after that**

• Principle 2: Tape at night

Although I’m pretty crazy about all this breathing stuff, I try to maintain a decent balance of “normal life” as well.

I recently went to a Bachelor Party weekend and stayed in a house with about 10 other people. My sleep routine was out. But getting in some “breathing” wasn’t.

I didn’t have to look weird or do anything special. I taped up once I got into bed so very few would see. When I woke up, I put my headphones in and did 15 minutes of box breathing (in bed) using the iBreathe app. Finally, I laid there and did 5 static breath holds:

Hold 45 sec after exhale —> Rest 1 min
Hold 45 sec after exhale —> Rest 45 sec
Hold 45 sec after exhale —> Rest 30 sec
Hold 45 sec after exhale —> Rest 15 sec
Hold 45 sec after exhale —> End

The point of all of this is to show you that incorporating breathing exercises into your day is fairly easy, regardless of your situation. And the benefits are many.

Just a few minutes of slow breathing can increase heart rate variability, improve autonomic function, and reduce stress and anxiety.

And a few breath holds can improve immune function, improve insulin sensitivity, and increase O2 carrying capacity.

Breathing is not only one of the easiest self-care practices to perform, but it also provides the greatest return on investment.

While on vacation or during a “party weekend,” it might be easy to ignore our normal self-care routines. But, this is precisely when we need them the most.

In good breath,
Nick

———————————————————————————————————————

* My current Principle 1 practice is 15 minutes of box breathing. After 2 months, I’m up to a 10-10-10-10 box: 10 sec inhale, 10 sec hold, 10 sec exhale, 10 sec hold. (I started at 5-5-5-5)

** My current Principle 3 practice is 3-5 walking breath holds of at least 45 sec each. Then, I perform 2 minutes of Advanced Simulation of Altitude from the Oxygen Advantage®

Increase brain blood flow by 20%

Hi everyone,

Over the last month, we’ve learned several important aspects of intermittent hypoxia (IH). For example, IH increases immune function and the production and storage of nitric oxide.

Although we’ve only scratched the surface on IH, I want to wrap up the discussion (for now) with one of my favorites benefits: Increased brain blood flow.

Intermittent hypoxia increases brain blood flow by 20%

(Published in 2017 in Hypoxia. To read the full summary, Click Here)

The participants in this study inhaled air with 10% oxygen for 6 min to induce hypoxia. Then, they breathed normal room air for 4 min. This cycle was repeated 5 times.

Measurements were recorded during the first and fifth bouts of hypoxia:

They found that intermittent hypoxia increased brain blood flow by 20%(!)

Fractional oxygen extraction in the brain also increased significantly. Pretty remarkable.

How to use these findings in your life

Statistical analysis revealed that major increases in brain blood flow occurred when blood oxygen saturation dropped to ~86%.  We can achieve this (with practice) using breath holds. 

I recommend performing 3-5 breath holds, with a 1-min recovery between each one, approximately 10-30 minutes before a workout, competition, or presentation. The increased brain blood flow will help focus your mind and prepare you for what’s ahead.

In good breath,
Nick

P.S. Breath holds can be dangerous. Take a look at Principle 3 before getting started.

P.P.S. The ~86% finding won’t be universal. Sometimes I barely drop my O2 below 95% and still feel major enhancements in my focus and concentration. In my experience, simply performing a few cycles of mild-to-moderate breath holds is all that is needed to feel the benefits.

The protective effects of intermittent hypoxia

Hi everyone,

Happy (almost) Fall!

A few weeks ago, we learned that intermittent hypoxia increases nitric oxide (NO) production and storage.

The paper I’m sharing this week examines NO’s protective effects during hypoxia.

The protective role of nitric oxide during adaptation to hypoxia

(Read on website)

The experiment gradually adapted mice to a simulated altitude of ~5000 m (>16K ft).

After the acclimation, the mice nearly doubled their NO metabolites. Their NO storage significantly increased as well.

Hypoxia protects against NO-overproduction

They also gave a subset of mice a condition causing excessive NO, which dropped their blood pressure about 36 mm Hg. However, when the mice were acclimated to hypoxia, they only showed a 19 mm Hg drop.

Hypoxia protects against NO-deficiency

Mice given a condition of NO-deficiency (which increases blood pressure) also saw protective effects from hypoxia. Without hypoxia, their blood pressure increased ~80 mm Hg. With adaptation, it only increased ~20 mm Hg.

Overall, these results indicate that adaptation to hypoxia protects against both over- and under-production of NO.

The final sentence from their abstract sums up the benefits nicely:

“The data suggest that NO stores induced by adaptation to hypoxia can either bind excessive NO to protect the organism against NO overproduction or provide a NO reserve to be used in NO deficiency.”

In good breath,
Nick

The benefits of resistance breathing

Hi all,

When I first saw the breathing mask from the Oxygen Advantage, I swore I’d never use it. I thought wearing a mask for breathing was silly. What I love about breathing is its simplicity.

However, because I got the Sports Mask as part of the training a couple weeks ago, I gave it a shot. And now I’m hooked.

What the mask does:

• Adds resistance to your breathing

• Increases carbon dioxide tolerance

• Helps drop oxygen saturation

Your diaphragm is probably one of your most underworked muscles. The added resistance of the mask helps strengthen your diaphragm, leading to more efficient breathing.

The mask is also designed to pool carbon dioxide (CO2). If you’ve been following my work at all, you know the importance of CO2. The mask makes it easy to feel ‘air hunger’ without even trying. This will help build CO2 tolerance over time.

Lastly, because the mask limits air inflow, it also makes it easier to practice intermittent hypoxia. A brisk walk on the highest resistance setting easily drops me into mild hypoxia (SpO2 ~95%).

How I Use The Breathing Mask

I am currently using the breathing mask 2 times a day, for a total of ~10 minutes.

In the morning, I take around 15 big breaths (nasally) on the highest resistance setting as “inspiratory muscle training”. After this, I do a 4-minute workout of squats, push-ups, and plank, with the mask on the lowest resistance setting. This is surprisingly difficult.

At night, I do a series of stretches with the mask on the highest resistance setting.

———

Over the past 3 weeks, I’ve noticed that the exercises with the mask have gotten easier. I’m sure it’s partially a mental adaptation, but I also feel that my breathing is easier and my CO2 tolerance is increasing. (Note: My CO2 Tolerance Test score has increased from ~45 sec to around 67 sec, but I have made other changes, especially to my sleep, which have also helped.)

If you are at all interested in resistance breathing, I recommend you give it a shot. The benefits are real and quickly noticeable. Obviously, I’m a fan of the Oxygen Advantage® Sports Mask, but there are plenty of others out there. Just make sure you get one that supports nasal breathing.

In good breath,
Nick

P.S. The change I made to my sleep was to add 2-2.5 hours after dinner before going to sleep. The author of The Longevity Paradox recommends 4 hours, but that isn’t practical with my schedule. However, adding just 2 hours between dinner and bedtime has substantially improved my sleep and breath hold times. Besides taping, this might be the 2nd easiest change I have made that has substantially improved my overall quality of life.

The importance of tongue placement for breathing and stability

Hi everyone,

This week, I want to share a key takeaway from the Oxygen Advantage (OA) teacher training I attended a couple weeks ago.

Patrick McKeown (the founder of OA) is a wealth of knowledge. He’s been researching, applying, and teaching about breathing for nearly 20 years. It’s always an honor to learn from him.

Although I learned a ton, there was one thing that stood out this time: the tongue.

Your tongue should rest on the roof of your mouth, which will open up your airways. If your tongue rests down, it will restrict your breathing.

This is especially important during sleep. But, the only way to keep your tongue on the roof of your mouth during sleep is to make it a habit during the day. (I’m now trying to keep my tongue on the roof of the mouth as much as possible.)

However, knowing this science of tongue placement didn’t actually make me interested. What did was an exercise a physiologist led us through to demonstrate the importance of tongue placement for stability.

Here’s the exercise:

1. Let your tongue fall off the roof of your mouth.

2. Now, let your head fall back and look up at the ceiling.

3. Repeat, but with your tongue pressed against the roof of your mouth.

You should feel more head and neck stability when your tongue is pressed against the roof of your mouth. The physiologist explained how this stabilizes the neck and spine, but most of it was over my head. I just know it worked.

Some others in class noticed that their breathing was significantly easier when their tongue was on the roof of their mouth.

With that in mind, try noticing where your tongue rests throughout the day. Try keeping it pressed against the roof of your mouth. This will help your breathing and stability.

In good breath,
Nick

P.S. One more picture from the training. They say you should never meet your idols, but Patrick (right) never disappoints. In addition to all of his knowledge, he’s just genuinely a nice guy. It was awesome to learn from him again.

Nitric Oxide, Hypoxia, and Batman

Hi all,

Greetings from Lakeland, FL! We live near the east coast of FL, so we evacuated inland. My thoughts are with any of you affected by Dorian. Stay safe!

We learned last week that nitric oxide (NO) is a critical in areas of tissue hypoxia (see review here). With that in mind, what happens when we purposefully induce hypoxia via intermittent hypoxic (IH) training (Principle 3)?

Intermittent hypoxia increases production and storage of nitric oxide

(Read on website)

In this study, mice were gradually adapted to an altitude of ~5000 m over a 40-day period.

After acclimation, their NO metabolites (nitrite and nitrate) increased significantly.

• This indicated that either (1) more NO was being generated or (2) NO was being released from storage.

However, the mice also increased their NO storage considerably.

• The increase in NO storage correlated significantly with the increase in NO metabolites.

All together, these results indicate that adaptation to intermittent hypoxia increases NO production and storage.

The storage rate was higher than the production rate, which was likely a protective mechanism to ensure that blood pressure did not drop too low.  However, the large storage also ensured that NO could be readily released if needed, highlighting yet another benefit of adaptation to hypoxia and intermittent hypoxia training.

In good breath,
Nick

P.S. Speaking of IH training, here’s a shot of me wearing the Oxygen Advantage® Sports Mask at the teacher training last week. Yes, I look like Bane, but it adds a lot of resistance to each breath, which helps improve CO2 tolerance, increases breathing muscle strength, and allows me to drop into hypoxia easier.