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The Universal Breath

Alastair Hill is an expert in helping people make changes to fears, anxiety and PTSD-symptoms.

He first began his journey into psychological change in 2008 after seeking solutions to his own experiences of depression and social anxiety and, upon overcoming his own stresses, discovered a natural talent for helping others through theirs.

He has worked extensively with military personnel through the charity Rock2Recovery where he has helped hundreds of veterans and currently serving members of the British military find lasting relief from psychological stress.

Alastair also runs a private practice in North Hertfordshire.

www.alastairhillhelps.com

The Universal Breath

Possibly the only breathing exercise you need to know.

Have you ever got confused about breathing exercises and which one to do?

Should you do 7-11 breathing, Box Breathing, Wim Hof, 4-7-8 breathing or Buteyko?

I like to keep things simple in life, and after exploring a lot of breathing methods, there is one breathing technique that I have found to stand head and shoulders above the rest. It is sometimes called Coherent Breathing, but here I’m calling it The Universal Breath.

There is some fascinating science that point towards its efficacy and I want to share the most interesting bits I’ve picked up with you.

What is The Universal Breath?

The Universal Breath has three components:
  • Breathing at 5 breaths per minute (inhaling for 6 seconds and exhaling for 6 seconds).
  • Breathing through your nose.
  • Breathing using your diaphragm; your belly should expand as you breathe in and relax as you breathe out.

Throughout this article are 1 minute practice sessions of The Universal Breath.  I really encourage you to use them and to try out the practice.  At the end are suggestions of apps that you can use for practicing.

My journey to breathwork

Since I was a teenager, I have had a lot of anxiety, suffered from sleep issues and frequently had low energy levels.

In early 2020 I stumbled across some information about how to breathe that transformed these issues for me. I experienced a big reduction in anxiety, have vastly improved my sleep, have improved focus, and have more energy than I have ever had in my life.

The benefits from learning to breathe well were much greater than I expected.

I have also seen many positive changes in other people who have incorporated the information I share here into their lives, and you may be able to get similar benefits too. I’ve seen this breathing method help profoundly in the recovery from PTSD and high levels of anxiety, to helping people to access states of flow and focus at work.

Why not give it a go?

Practice Exercise 1

Sit up straight, breathe through your nose, hit play and follow along.

Principle 1: Breathe Through Your Nose & With Your Diaphragm

I didn’t know it was possible to breathe poorly. However, it turns out that many of us are not breathing very well.

In my view, the biggest mistake you can make in how you breathe is to not understand the huge importance of breathing through your nose. The bottom line is, healthy humans breathe through their noses the vast majority of the time. This mean breathing through your nose at rest, during exercise and at night whilst you sleep.

Remember this rule: The mouth is for eating and talking. The nose is for breathing.

I had been a chronic mouth breather since childhood and it turns out that mouth breathing alone can contribute to chronic anxiety and health issues, like sleep apnoea.

If you frequently have a stuffy nose (as I used to), it can be worth doing a number of things to help you transition to nasal breathing:

  • Commit to becoming a nose breather. When I started out my breathing journey I proclaimed to myself “I am a nose breather” and I set my mind on the task of transitioning. It wasn’t an easy journey for me, and for many it takes commitment, but the pay-offs are huge.
  • Learn nose unblocking techniques. Simply go on to YouTube and try the techniques you find. (I found the nose unblocking technique taught by Patrick McKeown very helpful.)
  • Look at your diet or other aspects of your lifestyle to see if you are exposing yourself to allergens that stuff up your nose. I cut dairy out of my diet. Dust also bungs me up.
  • There may be medical interventions necessary like removing polyps. I decided to undertake some dentistry to widen my palate. Although I had already transitioned to nasal breathing when I decided to do the dentistry, widening my palate reduced a lot of my sensitivities to allergens. However, for most, these kinds of interventions are not necessary.

Nose breathing is also linked to diaphragm breathing. Diaphragm breathing is when your stomach expands as you breathe in and relaxes as you breathe out. It is easiest achieved when breathing slowly. The faster you breathe, the more likely you are to breathe with your upper chest.

If you look down at your chest and breathe in quickly through your mouth, you are likely to see your upper chest expand. Try it. Mouth breathing often triggers upper chest breathing.

If you look down at your chest and breathe in through your nose, you are likely to see your lower chest and belly expand. Nasal breathing naturally stimulates diaphragm breathing. The nose also naturally slows your breathing, making diaphragm breathing easier.

Often when someone I’m working with habitually breathes through their mouth, I set them on a journey to become a nasal breather and have had so many people say what a huge difference it has made to their stress levels and clarity of mind that I’m amazed this information on nasal breathing is not more widely shared in resources about dealing with anxiety.

Here are two pictures of me around aged around 7 and 17.

You can see possible effects on my face from breathing through my mouth in these two pictures. My face at 17 is a lot longer, whereas my face at 7 was rounder. Nose breathers tend to rest their tongue in the roof of their mouth, which effects the growth of the face and teeth through the pressure that the tongue places on the growing maxilla (upper jaw). The pressure of the tongue widens the palate, creating space for the teeth, and pushes the upper jaw forward, preventing it from sinking downwards and creating a rounder face. When the tongue rests in the bottom of the mouth, which happens whilst mouth breathing, the face grows downwards and longer.[1]

One of the biggest issues I had in nasal breathing was sensitivity to allergens and this likely related a lot to the effects of mouth breathing on my jaw. My palate was so narrow that it arched up very high into my nose meaning that only the smallest amount of inflammation would hamper my ability to nose breathe. Getting some dentistry to expand my upper jaw and widen my palate has improved my breathing and reduced my sensitivity to allergens, but is not necessary for most.

Principle 1: Breathe Through Your Nose & With Your Diaphragm

Here are some of the benefits of nasal and diaphragm breathing[2]:

  • Nasal breathing, compared to mouth breathing, results in 10-20% more uptake of O2. Why?
    • The nose imposes approximately 50% more resistance on the air stream to the lungs than mouth breathing, this naturally slows your breathing which gives more time for oxygen to reach the small air sacs in the lungs where oxygen transfer to the blood takes place.
    • Diaphragm breathing carries more air to the lower lungs. The lungs are triangle shaped, pointier at the top and wider at the bottom, leading to greater transfer of oxygen into the bloodstream due to the greater surface area in the lower lungs.
    • Due to gravity, there is also more blood in the bottom of the lungs, again leading to greater oxygen transfer to the blood.
    • The nose releases a hormone called nitric oxide which helps redistribute blood evenly across the lungs, meaning that there is also greater transfer of oxygen in the upper lungs when nose breathing compared to when mouth breathing.
    • Nitric oxide also opens up the airways.
  • Nasal breathing and diaphragm breathing lowers stress
    • The brain monitors the speed of your breathing. Faster breathing sends signals of agitation to the brain. Slower breathing sends calming signals to the brain. Mouth breathing is faster and nose breathing is slower.
    • Mouth breathing can easily lead to over-breathing. If you breathe rapidly, you lower the level of carbon dioxide in your blood stream, which in turn leads to a constriction in cerebral arteries, which in turn leads to difficulty thinking clearly and can cause anxiety. This is why you feel light-headed when you hyperventilate. Mild or acute hyperventilation happens much more easily when you are a mouth breather.
    • Chronically over-breathing can also lead to an anxiety trap by creating a sensitivity to CO2. The urge to breathe is actually triggered by CO2 accumulating in the bloodstream, not oxygen depleting. And people who over-breathe expel so much CO2 that they develop a sensitivity to it, and so you feel out of breath really easily when CO2 levels rise. And the trap is that feeling out of breath usually prompts people to breathe harder, which further lowers CO2 levels and maintains the body’s sensitivity to it. When I was a mouth breather, I would feel breathless all the time despite breathing much faster than I do now. And feeling breathless is stressful!
  • Nasal breathing and diaphragm breathing is healthier
    • The nose filters, warms and moistens the air, offering a first line of defence from unwanted particles entering the lungs.
    • You’re more likely to have a dry mouth when mouth breathing which increases the chances of dental cavities, gum disease and bad breath.
    • You breathe out 40% more water vapour breathing through your mouth leading to greater dehydration.
    • Diaphragm breathing stimulates faster recovery after exercise.
    • Nitric oxide, which is released by the paranasal sinuses, has anti-bacterial, anti-viral and anti-fungal properties, sterilizing the air you breathe.
    • Nitric oxide dilates your arteries and improves blood pressure.
    • There are also studies underway that suggests that nitric oxide prevents infection from Covid-19.
  • Better sleep
    • Snoring and sleep apnoea are highly correlated with mouth breathing at night.
    • Nose breathing at night leaves you much more rested in the morning due to it being calmer sleep (slower breaths) with better oxygenation of the body.

Before I began my breathing journey, I had an intuition that being unable to breathe through my nose was somehow linked to my stress levels and stopped me sleeping well, I had no idea of all the other benefits that go with nose breathing.

Here are some common signs that you mouth breathe a lot or breathe too quickly:

  • You cannot sit, walk, sleep or do exercise breathing through your nose.
  • You feel out of breath easily.
  • You often get light-headed standing up.
  • You wake up in the morning with a dry mouth.
  • You snore or have sleep apnoea.
  • You frequently get dry lips.
  • You frequently have a stuffy nose.
  • You breathe much faster than other people.
  • You often feel anxious or stressed for reasons that don’t seem linked to emotional causes.

Practice Exercise 2

Sit up straight, breathe through your nose, hit play and follow along.

Principle 2: Breathe Rhythmically

There is a concept in biology called entrainment. Entrainment is the phenomenon where a rhythm in one biological system causes another biological system to fall into synchrony with it.

For example, mosquitoes beat their wings in synchrony with each other, when you are walking side by side with someone you often start walking in time, and people experiencing a deep emotional connection with each other often start to breathe at the same rate (their hearts may beat at the same rate, too).

And a fascinating thing happens when you breathe at a regular repeating rhythm. The regular rhythm of your diaphragm creates a regular pattern of speeding up and slowing down of your heart beat (known as Respiratory Sinus Arrhythmia). (Breathing in speeds up your heart rate and breathing out slows down your heart rate.) Other bodily systems then fall into synchrony with your heart rate and diaphragm movements creating synchronistic changes in your blood pressure, skin conductivity and patterns of neuronal firing.[3]

Systems use less energy and run more efficiently when they are internally synchronised. Dr Alan Watkins in his excellent TEDx talks (link in footnotes) argues that the human system moves from inefficient and unpleasant to efficient and pleasant depending upon the level of “cardiac coherence” (how synchronised the body is with the heart.

And the way to create cardiac coherence is through a repeating breathing rhythm.

We now have three essential elements of healthy breathing:

  • Nasal breathing
  • Diaphragm breathing
  • Breathing in a regular repeating rhythm

There is one more element to add to make The Universal Breath.

Principle 3: 6 seconds In, 6 seconds Out

The life scientist Stephen Elliot discovered the magic of a 6-seconds-in, 6-seconds-out breathing rhythm whilst trying to create the so called “Awakened Mind” brain wave pattern in himself.

The Awakened Mind brainwave pattern is a brain state associated with “higher states of awareness” and was discovered by biophysicist, clinical psychologist, doctor, and zen master C Maxwell Cade after measuring the brainwave patterns of many experienced contemplatives, long-term meditators, swamis, yogis, Zen masters and healers[4].

Stephen Elliot, after much trial and error, found that a 6-seconds-in, 6-seconds-out breathing pattern helped him to reliably recreate this brain wave pattern in himself. The breathing pattern seems to naturally create a calming effect and a meditative type state.

What’s so special about this particular speed?

Here are some selected bits of information that you may find interesting.

The Effect of the Universal Breath on your Autonomic Nervous System & Heart Rate Variability

You may have heard of something called your Autonomic Nervous System (ANS). It’s the part of your nervous system responsible for operating many of the involuntary functions of your body including heart rate, blood pressure, digestion and arousal level. It’s a very important system in the body!

The ANS is divided into the sympathetic and parasympathetic systems. The sympathetic system is typically involved in processes that require quick responses and is responsible for our “fight or flight” response. It’s also the system that gets stuck on overdrive when we are anxious and stressed. The parasympathetic system is associated with functions that do not require immediate action, including resting, digesting good and sexual arousal. When you are relaxed and feel good, your parasympathetic system will be engaged.

The problem that most of us face in life is that the sympathetic side of our nervous system is over activated. We didn’t evolve at the top of the food chain (despite us being there now) and so our nervous systems seem to be tilted towards a tendency to threat processing (and getting stressed).

And, quite incredibly, one of the main cues that your ANS receives that tell it how to be activated is the frequency and depth of your breathing. How can scientists tell this? By tracking how your breathing affects your Heart Rate Variability (HRV) – which, so I read, is the best non-invasive way of measuring the functioning of the autonomic nervous system[5].

On a quick side note, if you are breathing regularly as you read this, a typical rate to breathe is at 15 breaths per minute, this is actually giving a cue to your autonomic nervous system to put an emphasis on the “sympathetic” side. Eek! Best to learn a little more about breathing well.

So, what is Heart Rate Variability? HRV is a measure of how much variance there is in your heart rate.

The more stressed a person is, the lower their HRV scores tend to be, i.e. the less their heart beat varies. And a high HRV score is a sign that someone has a good balance between their sympathetic and parasympathetic systems, including a good stimulation of their parasympathetic system.

And it turns out that breathing at 5 breaths per minute, in for 6 seconds and out for 6 seconds, creates a very high level of HRV. Stephen Elliott in his book The New Science of Breath argues that it creates “an HRV signature of maximal amplitude” compared to other breathing speeds[6].

It creates a natural state of calm when practiced at rest, demonstrated not just subjectively in how you feel, but also biologically in your HRV. A scientifically demonstrated way of turning down stress and turning on calm. It can take a little practice to get used to, but when you do, it becomes a tool that you can always turn to.

Bud Craig and the Insula

Another example of the power of breathing at 5 breaths per minute comes from a study where activity in a part of people’s brains called the insula was measured whilst they breathed at different speeds as they looked at positive and negative emotional images.[7]

The insula is hypothesized to be partly responsible for our concept of self-awareness, including awareness of our bodies and emotions and how they interact to create our perception of the present moment.[8]

There is a right and a left side to the insula and each side seems to be involved in the processing of different types of emotions. To quote the authors of the study, Bud Craig and Irina Stirgo[9]; “the left anterior insula and anterior cingulate are associated predominantly with parasympathetic activity, positive emotions and ‘energy enrichment’, whereas the right anterior insula and anterior cingulate are associated predominantly with sympathetic activity, negative emotions and ‘energy expenditure’.”

Subjects breathed at either 5 breaths per minute (The Universal Breath) or 20 breaths per minute whilst looking at positive and negative emotional images.

Whilst looking at positive images people breathing at 5 breaths per minute had more activation of the left insula (the positive feeling side) when seeing the positive images and less activation of the right insula (the negative feeling side) when seeing the negative images compared to when they breathed at 20 breaths per minute.

In simple terms, that means that people formed a positivity bias when breathing at 5 breaths per minute; their brains showed an increased response to the positive and decreased response to the negative.

What more could ask for from a breathing pattern?!

How about some benefits to physical health as well …

Practice Exercise 3

Sit up straight, breathe through your nose, hit play and follow along.

The Diaphragm is a Pump

It’s long been a mystery to science how a giraffe is even alive. With its head 2 metres above its heart, and with an average-sized heart relative to its body mass, how does it get enough nutrients to travel up to its brain?

Well, in 2009 the already-mentioned life scientist Stephen Elliott was given an opportunity to test a hypothesis that it is a giraffe’s diaphragm that is responsible for getting the majority of the blood up to the giraffe’s head, rather than its heart. The Dallas Zoo needed to anaesthetize a giraffe called Jade to trim her hooves and invited Stephen Elliott to test his hypothesis whilst she was laid out on the ground. The data he collected confirmed that blood flow to Jade’s head moved in time with her breathing pattern[10]. And, interestingly, it also turns out that a giraffe has a very large diaphragm relative to its body mass.

Lesson: the diaphragm pumps blood in addition to the heart. And this applies to humans too.

When you breathe in, your diaphragm expands your lungs, and this expansion pulls blood from your body into your lungs. When you breathe out, your diaphragm compresses your lungs and pushes blood out of your lungs and into your body.

What does this have to do with The Universal Breath?

Well, a bit like a giraffe, your head is located high above your heart and the movement of your diaphragm helps to circulate blood effectively to your brain as well as to all other areas of your body.

The health of every cell in your body depends upon good circulation as circulation provides each cell with the energy and nutrients needed for healthy functioning.  And, according to research also conducted by Stephen Elliot, breathing at a rate of 5 breaths per minute creates a peak level of blood circulation and oxygenation of the body, including oxygenation of the brain.

It’s not too much of a leap from here to suggest that The Universal Breath helps your body and brain to run optimally and for you to think clearly. In the words of James Nestor, author of the excellent book Breath: “It doesn’t matter what you eat, how much you exercise, how skinny or young or wise you are, none of it matters if you’re not breathing properly.”

I have had clients reporting a clarity of mind and calmness that they have never felt before in their lives just from regular practice of nasal breathing and the The Universal Breath. And for me, I have a level of energy and vitality that is now mine and here to stay thanks to practicing healthy breathing every day.

Troubleshooting

Does it have to be 6 seconds in and out?

Does it have to be 6 seconds? No, not exactly. Although it seems that there is a sweet spot between 5 and 6 seconds that has a near universal effect on people.

For some people starting at 5 seconds in and out is easier. And, if 5 seconds feels too slow and difficult, I recommend practicing doing slow breathing with longer exhales at first.

For example, breathing in for 3 seconds and out for 5 seconds, or breathing in for 4 seconds and out for 6 seconds. Making the exhales longer, makes for a more calming breath, and is a good practice to start with if you feel stressed doing 5 seconds in and out.

Once you can comfortably breathe slowly using longer exhales, then move on to The Universal Breath.

How do you ensure nasal breathing at night?

The way to guarantee this is to tape your lips closed before you go to sleep. I’m not joking. This is a very common practice amongst people that get into breath retraining and it was an important step in my journey. My sleep quality and energy levels improved massively from this alone.

You can take baby steps with it.

You can apply a tiny dab of tape just as a reminder. You can tape your lips during the day whilst watching TV to get comfortable with it for a while before doing it at night. You can just tape your lips for the first few hours of the night until you wake up, then take the tape off for the rest of the night. You can also use nasal dilators (like Breathe Right strips) to open up your nose each night (I use these each night).

I use 3m Micropore tape.

The benefits of nasal breathing at night are HUGE, and I highly recommend getting comfortable with the idea of taping your mouth shut at night and trying it out. From my experience I suggest that a person will never sleep their best breathing through their mouth; the best night’s sleep you can have is one where you are breathing through your nose.

I got panicky during the exercises!! It was too slow for me.

This is absolutely fine if this is your experience. Firstly, I recommend seeking out medical advice first before following any suggestions I share below. There can be underlying medical reasons for why it is difficult to breathe slowly that require diagnosis and treatment by medical professionals.

For you information though, I will share how I overcame this difficulty in myself.

I found exercises like The Universal Breath too difficult when I started my breathing journey. And, in my case, this was caused by habitually over-breathing (due to mouth breathing) and becoming overly-sensitive to carbon dioxide building up in my bloodstream. CO2 is what stimulates the urge to breathe and it creates uncomfortable sensations that can build up to a feeling of panic when you’re not used to higher levels of CO2 in your body. The way forward is to do breathing exercises that recondition your response to carbon dioxide accumulating.

It was also absolutely essential for me to commit to breathing through my nose at all times.

Although this might sound like a lot of work, if you are in the position I was in, you have the most to gain from doing breath retraining. For me, it was like waking up from an awful dream once I had gotten through it.

The types of exercise that I found useful for retraining my response to carbon dioxide came largely from the Buteyko Method. In particular, doing long-exhale exercises and some breath holding. Though I found long-exhale exercises to be the most useful.

Long-exhale exercises are as they sound; in these exercises you aim to have longer exhales than inhales. You can start off somewhere manageable, like breathing in for 3 seconds and out for 5 seconds (if this is too hard, just make the numbers smaller), and gradually increase the numbers across time. I did lots of exercises like this and it’s where I recommend people begin.

I found a technique called “Triangle Breathing” helpful also, where you breathe in, breathe out, and then pause for an equal number of seconds. For example, breathing in for 3 seconds, out for 3 seconds, and pausing for 3 seconds. Then gradually building up to doing 4-4-4, then 5-5-5, etc. This is something I started doing later on once I’d made progress doing longer exhales.

A benefit of longer exhale exercises or Triangle Breathing is that they are naturally calming. Exhaling slows the body down, and so breathing with longer exhales (or pausing after the exhale) often leaves you feeling very chilled. I recommend getting a breathing pacer app (like Paced Breathing Pro if you have Android) and doing several 10 minute exercises each day, until you can comfortably breathe slowly.

And, of course, committing to breathing through your nose at all times (including at night).

Practice Exercise 4 - ALTERNATIVE WAY OF PRACTICING

Sit up straight, breathe through your nose, hit play and follow along.

Summary & Ways To Practice

So, these are the key components of The Universal Breath:

  • Breathing at 5 breaths per minute (inhaling for 6 seconds and exhaling for 6 seconds).
  • Breathing through your nose.
  • Breathing using your diaphragm; your belly should expand as you breathe in and relax as you breathe out.

I hope I’ve given you good reason to try it out.

Here are the two ways I use to practice you have practiced in this article.

Using a Metronome

Hopefully you have listened to the first 3 exercises on this page and tried this. This approach is taught by the breath and yoga teacher Ben Wolff. I highly recommend looking him up if you want to learn more about breathing well. He is a walking encyclopaedia of knowledge on the breath, neuroscience and personal change.  

Set a metronome to click at 1 beat a second (60 bpm), and set it to accent every 6 beats (set it to 6/4 time). Either sit upright or lie on your back. Start your metronome and breathe in for 6 clicks, and out for 6 clicks. Do this for anywhere from 5 to 20 minutes.

I’ve attached downloadable instructions for setting up a metronome on Android and iPhones.

For Android Users

Click to download a set of instructions for setting up the "Simple Metronome" app for practicing The Universal Breath. It's a free app.

PDF Instructions for Android

For iPhone Users

Click to download a set of instructions for setting up the "Simple Metronome" app for practicing The Universal Breath. It's a free app.

PDF Instructions for iPhone

Using a Breathing Pacer App

There are various apps that you can get which make a chime or a sound indicating when to breathe in and out. Simply setup one of these apps with a 6 second inhale and a 6 second exhale. Get somewhere comfortable where you won’t be distracted, press start and gently breathe along.

My preferred app is on Android and is called Paced Breathing Pro. Exercise 4 on this page uses Paced Breathing Pro. It makes a soothing sound for breathing in and out, and I find that it’s possible to use this particular breathing pacer at the same time as doing lots of different activities. I use this app every day to create a sense of calm whilst reading, studying, driving, and also whilst writing this article!

For those of you with iPhones that really liked the Paced Breathing Pro tone. Here is a 30 minute audio of the tone you can download. For all Android users, please download the app. It only costs around £1.80 and it is more convenient that playing this mp3.

Possibly The Only Breathing Exercise You Need to Know

I started out this article with a bold claim – that this is possibly the only breathing exercise you need to know. I stand by that claim.

From my explorations I have found no other breathing exercise with such wide and well-proven benefits. It is also wonderful in that it is a fixed practice. With breathing practices like Buteyko or Wim Hof there can be a sense of needing to push yourself further and further; to hold your breath for longer and longer amounts of time, for example. But with the Universal Breath, once you can comfortably do the pattern (which for most takes very little time at all), there’s nothing else you need to learn. Just continue with this simple practice and the benefits will accrue.

The pattern seems to resonate optimally with the human system itself – creating calm, peak oxygenation and synchronisation of bodily systems.

If you want to expand upon it, you can add visualisations, like seeing energy flow around your body with the breath pattern. (For example, picturing coloured energy flowing up your spine to your head as you breathe in, and flowing back down to the base of you spine as you breathe out.) Or you can incorporate the Universal Breath into movement exercises.  

Or you can do none of those additional things and still get huge benefits.

Happy Breathing!

Footnotes

 [1] Kahn, Sandra & Ehlrich, Paul, Jaws: The Story of a Hidden Epidemic

[2] Much of the information here comes from Ley, R., Timmons, B.H. (Eds.), Behavioral and Psychological Approaches to Breathing Disorders, and also the work of Patrick McKeown who has synthesised a lot of information on the nose. I also recommend the excellent book Breath by James Nestor.

[3] Learn more in the book Coherence by Dr Alan Watkins, and his excellent TEDx talks Being Brilliant Every Single Day 1 & 2 (https://www.youtube.com/watch?v=q06YIWCR2Jshttps://www.youtube.com/watch?v=Q_fFattg8N0)

[4] Cade measured the brainwaves of over 4,000 people and had a particular interest in so-called “higher states of consciousness”. https://www.themindmirror.com/why-train-the-brain/the-awakened-mind/https://www.warrior.do/the-awakened-mind/

[5] Elliott, Stephen, The New Science of Breath – 2nd Edition, pg 21

[6] See footnote 5

[7] Strigo IA, Craig AD. 2016 Interoception, homeostatic emotions and sympathovagal balance. Phil. Trans. R. Soc. B 371: 20160010. http://dx.doi.org/10.1098/rstb.2016.0010

[8] https://www.neuroscientificallychallenged.com/blog/2013/05/what-is-insula

[9] See footnote 7

[10] https://coherence.com/Jade_A_Thesis_On_Giraffe_Circulatory_Physiology.pdf