How to Breathe Correctly for Optimal Health, Mood, Learning & Performance

Why we breathe: oxygen in, CO2 out -- but CO2 is not the villain you think

A common misconception is that CO2 is purely bad. You actually need CO2 to liberate oxygen from hemoglobin and deliver it to tissues.

"And of course we breathe in order to bring oxygen into the body, but we also breathe to remove certain things from our body, in particular carbon dioxide."

Mechanical breathing system: nose, mouth, larynx, diaphragm, and intercostals

Understanding breathing mechanics -- lungs, diaphragm, intercostals -- unlocks control of stress, focus, sleep, and mood.

"When we're thinking about the respiration system, we also need to look at the mechanical system."

Physiological sigh explained: double nasal inhale + full mouth exhale

Two deep nasal inhales to maximally inflate the lungs, followed by a full exhale through the mouth to lungs empty.

"And then the second one after that is a quick, sharp inhale to maximally inflate your lungs, followed by a full exhale through the mouth to lungs completely empty. So it's big inhale through the nose, then short inhale through the nose immediately after that in order to maximally inflate the lungs, and then a long exhale through the mouth until your lungs are empty. You will understand why that particular pattern of breathing and not simply one inhale or not simply an inhale through the nose and an exhale through the nose as well is optimal for reducing your stress quickly. That double inhale through the nose and an exhale through the nose as well, is optimal for reducing your stress quickly. That double inhale through the nose, followed by a long exhale through the mouth, works to reduce your levels of stress and lower your levels of so-called autonomic arousal very fast in real time, and it works better than any other known approach. It's not a hack. This is actually something that your body has specific neural circuits to do, and it actually better than any other known approach. It's not a hack. This is actually something that your body has specific neural circuits to do, and it actually performs during sleep on a regular basis and even throughout the day, and that you can perform voluntarily."

Nasal vs. mouth breathing: incredible advantages of being a nasal breather most of the time

The nose and mouth are the only two air entry points.

"We'll talk about the incredible advantages of being a nasal breather most of the time, but also the incredible advantages of using your mouth to breathe during particular endeavors."

You need CO2 to liberate oxygen from hemoglobin -- the Bohr effect

Carbon dioxide is essential for oxygen delivery. Without adequate CO2, hemoglobin holds onto oxygen too tightly and tissues become oxygen-starved.

"You require carbon dioxide in order to liberate oxygen from hemoglobin."

High altitude: low air pressure means more breathing effort and CO2 disruption

At high altitudes, the O2/CO2 balance is disrupted because more energy is needed to inhale equivalent oxygen.

"If you're at a high altitude and the air pressure is very low, you have to put a lot of energy into breathing air into your lungs to get an equivalent amount of oxygen."

Opioid overdose kills by shutting down the pre-Botzinger breathing center

Fentanyl and opioids bind to receptors in the pre-Botzinger complex and shut down autonomous breathing, the primary overdose cause.

"You want to breathe in a healthy manner at rest. The best way is to spend maybe a minute each day paying attention to how quickly you are breathing per minute."

CO2 tolerance test: time your full exhale to assess your breathing health

Exhale fully and time it. Under 20 seconds = low CO2 tolerance, 20-50 = moderate, 50+ = high. This is independent of cardiovascular fitness level.

"And if, for instance, you were able to go 50 seconds or longer for that discard until you hit lungs empty, you have a fairly high degree of carbon dioxide tolerance."

Box breathing matched to CO2 tolerance: 3, 5, or 8-10 second intervals

Use your CO2 tolerance test result to set box breathing intervals -- low tolerance uses 3-second boxes, moderate uses 5-6, high uses 8-10 seconds.

"If you had low carbon dioxide tolerance, 20 seconds or less, you're going to write down the number three. Moderate, write five to six. High, eight to ten."

Box breathing retrains your resting breath pattern to use fewer, fuller breaths

Box breathing translates into a healthier unconscious breathing pattern by encouraging phrenic nerve control and nasal breathing at roughly 6 liters.

"You're encouraging phrenic control over the diaphragm, and you're getting that six liters of air per minute using fewer and fewer breaths over time."

5 min/day of cyclic sighing reduces stress more effectively than meditation

A Stanford study found 5 minutes daily of breathwork (especially cyclic sighing) outperformed meditation for reducing 24-hour stress levels.

"Any number of different breathwork practices done for five minutes a day outperformed meditation in terms of the ability to reduce stress around the clock."

Stanford study: breathwork beats meditation for stress reduction

Three breathwork practices were compared to meditation. All three breathwork methods outperformed meditation.

"What we found was that any number of different breathwork practices done for five minutes a day outperformed meditation in terms of reducing stress."

How exhales slow heart rate: diaphragm compresses heart, blood accelerates, vagus signals

When you exhale, the diaphragm moves up and compacts the heart, accelerating blood flow.

"When you reduce the volume of the heart, blood flow through the heart accelerates. The brain registers that and sends a signal to slow the heart rate down."

Respiratory sinus arrhythmia: heart rate rises on inhale, drops on exhale

Heart rate naturally fluctuates with breathing -- speeding on inhale, slowing on exhale. Emphasizing exhales activates the parasympathetic system.

"The opposite is true when you exhale. When you exhale, your diaphragm moves up, your rib cage tends to move inward a bit, and you compact the heart. You reduce the volume of the heart overall."

Physiological sigh engages intercostals and diaphragm -- feels like a sharp second inhale

The double inhale requires active engagement of intercostal muscles and diaphragm.

"It feels like the only way I can describe it really is as a sharp second and third inhale, because you really have to engage the musculature of those intercostal muscles in the diaphragm in order to do it. And then that long exhale can be through the nose or the mouth, but I find it particularly relaxing or even pleasant to do it through the nose. This method of three can be through the nose or the mouth, but I find it particularly relaxing or even pleasant to do it through the nose. This method of three inhales through the nose, followed by a long exhale through the nose or mouth will eliminate hiccups right away, because what it does is it hyper excites the phrenic nerve three times in a row, a very unnatural pattern for the phrenic nerve to fire. And then it undergoes a hyperpolarization, as we call it, in which the phrenic nerve actually stands a much lower probability of getting activated again for some period of time afterwards. So it is important that you try and return to normal cadence of breathing after doing this three inhales followed by the long exhale. If you need to perform it a second time in order to eliminate hiccups because they're simply not going away, that's fine. You can do that. But as far as we know, this is the most efficient and science-supported way to eliminate hiccups. Now, up until now, I've been talking about breathing techniques, and I've mainly focused on breathing techniques that emphasize the exhale, whether or not it's the carbon dioxide tolerance test, whether or not it's cyclic sighing or the physiological sigh that you use in real time to reduce stress. One thing that we haven't talked about so it's cyclic sighing or the physiological side that you use in real time to reduce stress. One thing that we haven't talked about so much is cyclic hyperventilation. Cyclic hyperventilation, as you recall, is a bout of 25 or so breaths, inhaling deeply through the nose and then passively exhaling or sometimes actively exhaling, typically through the mouth. So it might look like this."

The sharp second inhale of the physiological sigh re-inflates collapsed lung sacs

The double inhale maximally inflates the lungs by reopening collapsed alveoli, which increases the surface area for gas exchange before the long.

"You really have to engage the musculature of those intercostal muscles and the diaphragm in order to do it."

Switching to nasal breathing improves health; mouth taping can help train the habit

Studies show inhaling and exhaling through the nose has distinct advantages.

"When people switch to becoming nasal breathers, whether by mouth taping or doing cardiovascular exercise with mouth closed, the benefits are significant."

Inhale-emphasis breathing improves focus and information retrieval

When inhale duration exceeds exhale duration, the brain shifts into a more focused mode with better memory access.

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