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Writer's pictureLeah Taylor

Increasing Co2 tolerance levels - and why we should be interested…


Breathing.

It is something we all do, virtually non-stop, for the entirety of our lives, but is it a function of our bodies that we actually understand?

I’d like to say that we do, but it seems that very few of us truly appreciate the breath and even fewer of us understand all it can do for us when we optimise the way in which we use it. And, in hand with this, it is alarming how many of us are suffering the effects of under-utilising the power of the breath.


When investigating what each breath can do for us, a good place to start is the actual mechanisms behind taking a breath….what signals our body to breathe?

In large part, it comes down to the levels of CO2 in our body.

All cells in our bodies need oxygen to stay alive and to do their many jobs within the body. Added to this, all cells in our bodies produce Carbon Dioxide (CO2) as they do their many and varied jobs.

We take in oxygen-laden air with each inhale and we release CO2-laden air with each exhale – quite a basic summary of the work done (on a breath by breath basis) by our lungs and respiratory system.



Our circulatory system plays the role of delivering the oxygen we breathe in to all the cells of the body (via haemoglobin - red blood cells - once the oxygen has passed into the blood whilst in the lungs). This delivery system also includes picking up the waste product of cell activity – CO2 – and delivering it back to the lungs for release on our exhalations.

Depending on the way in which we breathe – our rate and rhythm of inhale and exhale – we will have a certain level of CO2 within our cells at any given moment.

In fact, without enough CO2 in our cells, the cells are unable to access the oxygen being delivered to them, as it is the CO2 in the cell which attracts the oxygen away from the haemoglobin in the bloodstream and into the cell.

And of course the exchange of CO2 occurs as well, with CO2 moving from the cell and into the blood, and the blood then continues on its way past the cell, through the body and back to the lungs and we exhale the bi-product of cell activity – CO2.




As I said, this is a very simplified explanation of the chemical mechanisms behind our breath, but still - pretty neat, right? A very clever system we have going on within us every minute of every day!


Each of us has a certain level of CO2 in our cells and therefore in our entire body at any given time, and the level we are able to tolerate before we feel the need to inhale will differ from person to person.

It is understanding our own personal CO2 tolerance level, which is important, as this tolerance level can have a big effect on the way in which we experience stress, manage our stress levels, manage our anxiety, and in doing so, support our overall health and wellbeing.

Having low CO2 tolerance levels has a very close correlation to having higher levels of generalised anxiety (something we call state anxiety).

Conversely, having higher CO2 tolerance levels has been shown to promote better stress response in individuals and lower rates of generalised anxiety.

Studies have shown that moderate to acute anxiety, especially when experienced over extended periods of time, (as can be the case if our CO2 tolerance is very low) negatively impacts many functions of our minds and bodies.

It arouses our Autonomic stress response, bringing us into a state of flight or fight (sympathetic arousal) and it inhibits cognitive performance, emotional processing and spatial working memory. It negatively impacts our systolic blood pressure/heart rate and impairs our ability to think/plan/organise our thoughts and draw from our memories. Whilst ever we are in a dominant sympathetic state we are also heavily limiting many other autonomic functions of the body – our digestive system, our hormone and reproductive system, our metabolism and circulation – everything takes a hit when we are in a heightened state of stress and anxiety, as our body prepares for fighting or fleeing to protect us.


So, the first big question….how do we work out our CO2 tolerance?

That’s easy – a few smart people have worked out a reliable test we can all do for ourselves to ascertain our personal co2 tolerance (see below).

But, something to remember - and to celebrate! – is that we are all capable of improving our tolerance to co2 and, therefore, also capable of decreasing our generalised anxiety levels and improving our ability to manage our autonomic responses to stressors in our lives.

And, even better, the ways to do it are not difficult or terribly time consuming. We need no special equipment or particularly taxing practices – we simply need to work on how we breathe.

And the benefits will come….think about the possibilities:

· decreased feelings of stress and generalised anxiety,

· increased mental clarity,

· improved digestion and hormone production/release (due to lower stress levels and more time spent in Para-sympathetic state),

· lowered blood pressure,

· increased cardio-pulmonary fitness,

· improved oxygenation of cells (known as the Bohr Effect),

· improved dilation of blood vessels which allows better movement of blood through the body,

· reduction in blood pH (also increasing the body’s ability to absorb oxygen)


All these possibilities just from increasing our CO2 tolerance levels!




And here’s the news - it’s such a simple and easy process to get an idea of your own CO2 tolerance and to then work at gaining improvement.

Ridiculously simple – all it takes is a little commitment to some regular breathing practices. Considering that we are all breathing all of the time anyway, it doesn’t strike me as a difficult task!

As you begin to feel the benefits of your practice, it’s a great idea to test yourself fairly regularly….as you improve your tolerance to CO2 you will no doubt notice lots of little things improving, not least of which will be your stress levels, your levels of anxiety and your ability to manage your responses to stressors, as well as your cardiorespiratory fitness.

I can’t find a single reason not to give it a go!


HOW TO IMPLEMENT THE CO2 TOLERANCE TEST

  1. Take 4 full breaths, 1 breath every 5-10 seconds: a 3-5 second inhale, followed by a 5-10 second relaxed exhale, 1 second pause before beginning to inhale again.

  2. At the top of the 4th inhale (totally full), start a timer and then exhale as slowly as possible. Stretch out the exhale for as long as possible. It’s helpful to close your eyes so that you can more effectively stay relaxed.

  3. Stop the timer when your air runs out, or when you need to inhale.

HOW TO INTERPRET YOUR RESULTS...

>80 seconds:

Elite - Advanced pulmonary adaptation, excellent breathing control, excellent stress control

60-80 seconds:

Advanced - Healthy pulmonary system, good breathing control, relatively good stress control

40-60 seconds:

Intermediate - Generally improves quickly with focus on CO2 tolerance training

20-40 seconds:

Average - Moderate to high stress/anxiety state, breathing mechanics need improvement

<20 seconds:

Poor - Very high anxiety and stress sensitivity, mechanical restriction possible, poor pulmonary capacity


And, now you have your tolerance level, it’s time to answer the second big question….

How do I begin to increase my CO2 tolerance ?

This part is easy – begin gently with some breathing exercises (as listed below) and, as you improve, take them from the gentle versions of the exercises to the more vigorous versions, with longer breath counts and holds.

You are working with YOUR breath here, so be sure to always take notice of how the practices make you feel and honour your own body and mind. There is no rush – the best of improvements occur with patient, consistent practice, so please be kind to yourself.


Practices to improve our co2 tolerance


1. BREATHE THROUGH YOUR NOSE!! It sounds too simple, but this is the number one, every day practice we should all be maintaining as much as possible, to increase our CO2 tolerance (among other amazing benefits!)

Wherever possible, close your mouth and breathe through your nose. Just doing this seemingly insignificant thing, slows the rate in which we offload the breath, therefore the co2 from our bodies, therefore gently increasing our ability to tolerate CO2.


2. Counted breathing exercises.

Importantly – always breathe through the nose for both the inhalations and the exhalations!

Sit down in a quiet area, set a timer for 10 minutes, close your eyes, and use the following breath-count guidelines.

a)Breathe with the same pattern over and over until the timer runs out.

i.Beginner:

Lengthened exhalation.

Exhale slightly longer than you inhale. A good starting place would be to inhale for 8 seconds and exhale for 10 seconds, however you need to begin with a count that is comfortable for you and slowly work up to longer counts with practice. Over time you might be able to increase the exhale until it is double the length of the inhale.

ii.Intermediate:

Exhale longer than inhale, and utilize a breath hold at the top of each inhale.

A good starting place would be to inhale for 8 seconds, hold your breath for 4 seconds at the top of the inhale, and exhale for 10 seconds. Again, though, it’s important to begin with a count that is comfortable for you and to slowly build up over time and practice.


iii.Advanced:

Exhale much longer than inhale, and utilize a breath hold at the bottom (and top as well if you want the extra challenge) of the exhale.

A good starting place would be to inhale for 8 seconds, (maybe hold the breath in for 4 seconds if you would like the double hold) exhale for 10 seconds, and hold your breath for 4 seconds at the bottom of the exhale.


b)Box Breath

This is where we utilise 4 sides of the breath rather the usual 2 (hence the shape of the box/square)

Inhale, hold, exhale, hold.

A good place to start would be a count of 6 for each section of the breath, making sure to keep each side of the breath equal value, but again it is important to begin with a count which is comfortable and then work your way to a longer count over time.

As you practice this exercise, you can gradually increase your count (always keeping all 4 sides of the breath equal) as you develop comfort with the lengthened counts.


c)Interrupted Breath (in yoga, this practice is called Viloma)

We can practice the interruption on the inhale or the exhale.

First begin to lengthen the natural breath and even it out, creating equal inhale and exhale.

Next, begin Ujjayi breath for a minute or so. This is where we slightly contract the muscles of the back of the throat in order to narrow the airway, creating a soft sighing sound with the inhale and the exhale. The breath shouldn’t be forced or strained, but should sound and feel even throughout the entire length of the inhale and exhale.

- If practicing the interruption on the inhale, divide the inhale into 4 stages (4 quarters) and, still in ujjayi:

Inhale one 4th of the breath, pause, hold for a few seconds,

Then inhale the second 4th of the breath, pause and hold for a few seconds,

Inhale the third 4th of the breath, pause and hold for a few seconds,

Inhale the last 4th of the breath, pause and hold for a few seconds

Exhale fully, in ujjayi. Inhale, exhale and then return to the viloma inhale on the next inhale (every alternate inhale is viloma)

- If practicing the viloma on the exhale, divide the exhale into 4 stages (4 quarters):

Exhale one 4th of the breath, pause, hold for a few seconds,

Then exhale the second 4th of the breath, pause and hold for a few seconds,

Exhale the third 4th of the breath, pause and hold for a few seconds,

Exhale the last 4th of the breath, pause and hold for a few seconds

Inhale fully, in ujjayi. Exhale, inhale and then return to the viloma exhale on the next exhale (every alternate exhalation is viloma)



3. Nasal breathing during training/exercise

Whilst exercising most of us tend to begin breathing through the mouth at a certain point of exertion - as our need for more oxygen increases with our body’s production of more carbon dioxide during higher rates of activity.

So, a simple way to train yourself to tolerate slightly higher levels of co2 is to close your mouth while exercising and breathe only through the nose, forcing your body to offload CO2 at a slower rate than you might be used to, as well as to take in air at a slightly slower rate than you would naturally be used to whilst mouth breathing.

Always be cautious when practicing this for the first times, and don’t push too hard when learning this technique. It might be a good idea to begin with walking rather than running or cycling to practice this breathing technique for the first few times. It can feel a little uncomfortable to begin with, but as your tolerance for CO2 lifts, so do your comfort levels with the practice.


So there you have it…some really easy practices we can all do to benefit ourselves. I am always amazed at the differences I feel within myself when I return to these practices. Like everyone, I have periods of time when I practice every day and other periods where it slips off my radar (or gets pushed off by too many other things vying for my time!)

I can definitely notice the improvements kick in again when I revisit my regular practice of some of these techniques – for me the most noticeable is the improvement in my mental clarity and ability to plan, stay focused, and stay calm in moments of pressure.


I’d love to hear from you – what do you notice when you regularly practice these techniques?

I’m fascinated and inspired by all the little things we can do for ourselves to improve our health and quality of life. So many of them are simple, small habits…and yet, when put together with other small habits, these small things begin to make a big difference.

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