3 Benefits of CO2 for Your Body

CO2 Saves Lives

CO2 is bad for us, right? Scientists and doctors have told me its a “waste gas” after all. Our job in breathing is to inhale more oxygen and “get rid” of carbon dioxide. Its a toxin that’s bad for us.

But is that the whole story to CO2?

Is there any reason why we generate CO2 in our bodies from metabolism?

Can it be that CO2 is actually important to life?

Harnessing the benefits of CO2

In reality, nothing is good or bad. We just label it that way.

Take any difficult situation you’ve been through in life. It sucked at the time. It was a pain in the ass. But now that you’re through it, you realise it was the making of you. You realise that you needed to go through that experience to grow. In hindsight, it wasn’t ‘bad’, it was just difficult at the time. In hindsight, it was possibly the best thing that ever happened, right?

This is what happened me with asthma. As a kid, I thought asthma was the worst thing in the world.

“Because” of asthma I couldn’t train for half the year.

“Because” of asthma I had to take medications.

“Because” of asthma I missed out on school, parties, holidays and life.

But as it turned out for me, asthma saved my life. Once I figured out what asthma was, why I had it and how to manage it, then I discovered that asthma was a saviour to me.

changing perspective

Asthma is a protective mechanism to save my life.

Asthma prevents other, more serious diseases, developing in my body.

Asthma indicates to me how I’m living my life in accordance with the health of my body.

Asthma tells me how likely I am to gain from training & how hard I should be training.

Like asthma, CO2 is misunderstood in our world.

We think it’s just a waste gas. We think it’s a nuisance. We think we’d be better off without, that it just needs to be expelled from the world. But, once we learn what it’s about; we then learn to harness its benefits. Benefits like:

Increased endurance.

Developing bigger and stronger muscles.

Better acclimitization to altitude.

More parasympathetic dominant nervous system.

Lungs that feel open and free to breathe.

Here’s 3 ways CO2 works in the body for your benefit…

1.       CO2 gets more O2 to your cells

We all know oxygen is the molecule for life. Without oxygen in our brain for just thirty seconds we can lose consciousness. Without oxygen in our cells:

At one minute, our brain cells start to die.

At three minutes, brain damage becomes more likely.

At ten minutes, coma and long lasting brain damage are inevitable.

At 15 minutes, survival is almost impossible.

But what we are talking about here, is oxygen in our cells, not oxygen in our lungs.

human lungs

 We can breathe all we like to get more oxygen in our lungs but that doesn’t mean the oxygen gets into our cells..

I’m afraid the process is just a little more complicated than that.  Think of the whole process of respiration like a bus journey to the city for a shopping trip.

To start the journey, I make my way to the bus station and pick up my ticket. I check the bus times and the platform from which my bus will leave. Once the bus arrives, I let some passengers get off while I jump onto the bus. I find a seat and chill for a while. I watch people get on and get off at their stops as I listen to some music and amuse myself with everything going on around me. Eventually, its my stop. I hit the bell, wait for the bus to stop, then jump off with everyone else.

This sounds pretty simple, right. Oxygen is taken into the body and prepared for its journey. It then jumps on its bus and into the red blood cells of the bloodstream, where its carried to its destination. Once it arrives there, it jumps off into the cell, ready to be used.  This is how it works in simplicity. And yet there’s a little more to the story….

Think of this analogy like making a bus journey for the first time. I actually remember this happen to me in Toronto. I had moved there back in 2013 to experience a big North American city lifestyle. I arrived in the country three days and was completely unfamiliar with my surroundings. It was my first day on my job and I had to get there by public transit…,.

On the Toronto buses, there are front doors and back doors to disembark.  By the time the bus arrived at my stop, it was jam packed with people. With the crowds blocking my way to the front, I headed to the back door. With plenty of time to spare, I dinged the bell and was ready to jump off. The driver stopped the bus, let people on and then pulled out to continue his journey. I was left standing at the back door like a gobshite – waiting for him to open it, like they do in Ireland. Instead, in Toronto, you’re supposed to open the back doors yourself!

I had now missed my stop and was running late for my first day in work – disaster.

At the time, I just wished I had a bus-worker acting as an usher to show me how the network operated. It would have been so much easier for me as a foreigner to be shown the custom for riding public transport in Toronto.

Now here’s the link between my story and CO2 – Carbon dioxide kind-of works like that magical bus-worker in your body.

Carbon dioxide ushers oxygen from your bloodstream to your cells.

It ensures oxygen arrives at its destination. If there is chronically insufficient level of carbon dioxide in your bloodstream (less than 5%), then oxygen acts like me making my way around Toronto. It misses its stop.

If oxygen continues to miss its stop, if it isn’t getting to the cells of the body, then you’re body thinks there isn’t enough O2 in your system. And so you’re brain tells your muscles to take in more air. This sets off a vicious cycle of wanting to breathe more air in and blow off more CO2. The cycle continues to drive less oxygen to your cells because there are no ushers for it to get to the cells, the CO2 threshold is lowered by the brain. The end result is the development of hyperventilation symptoms like allergies, asthma, anxiety, panic, depression, high blood pressure and many more. Up to 150 diseases of the body are associated with this syndrome.

“CO2 acts like an usher of O2 to your cells”

2. A rise in CO2 is your first stimulus to breathe, not a lack of oxygen

In everyday life and during sport, most people think “oh, ooo. I’m running out of oxygen so I need to breathe more air in”. And while this may be true at altitude, it is not the case normally.

The way your body really works is more like this: “I’m working bloody hard here, I’m generating way more metabolic by-products than I need and I need so let’s get rid of them, quick! If I don’t get rid of them, I’m going to die pretty fast.”

This means that the body’s impulse to breathe is a rise in CO2 levels first.

Let’s find out why by learning about the movement of Gases in the body.

Gas exchange is known as diffusion. It works by means of pressure and solubility. Simply, a gas moves from a high pressure environment to a low one and the gas which is more soluble, or smaller, moves more quickly.

more soluble gases move quicker: a fine ground coffee bean will dissolve quicker in water than a coarse bean.

high pressure gases move quicker: people will disembark a packed train to a near empty platform before anybody from the platform boards the train.

Think of diffusion like opening a can of soda.

soda spill

Soda is a carbonated soft drink stored under pressure in a can (carbon dioxide is added to it to make it fizzy and then sealed to keep the fizz in). When you crack open the can, the soda sprays into the atmosphere – the stored carbon dioxide is released, or diffuses, from a high pressure environment to a low pressure one – and the drink is characteristically fizzy. If you were to leave the soda stand for an hour it would become flat. Much of the stored carbon dioxide diffused from the open can to the atmosphere and the drink loses its fizz.  The reason why diffusion of CO2 is more important than diffusion of oxygen is because it is 26 times more soluble than oxygen. In other words, it is smaller and moves from areas of high to low pressure quicker than oxygen. So when pressure gradients are high for CO2 then it will diffuse first.


CO2 works the same in your body as it does in a can of soda. It is 26 times more soluble than O2, so it’s transfer from tissues cells (like muscles) to blood is far more rapid than oxygen.

 When the body exercises or metabolises food through the day it produces energy and lots of carbon dioxide as a by-product. This process builds the pressures of CO2 at the cell level (like the muscles) and once it reaches a certain pressure, it diffuses into the blood. When it moves into the blood, it displaces oxygen from haemoglobin in the red blood cell. Oxygen then moves from the blood into the cell (where its used for more metabolic work). This process is known in physiology as the Bohr effect.  It’s really important to understand because what it means is that:

A rise in carbon dioxide is your first signal to breathe more, not a lack of oxygen!

3. CO2 balances blood Alkalinity

The pH in extracellular fluid, and specifically the blood, is one of the most tightly regulated processes in the human body. As Atto Warburg, a Nobel prize winning researcher for cancer discovery, stated in 1931:  “disease can not exist in an alkaline environment”.  With a small pH range of 7.35 to 7.45, blood is slightly alkaline.

Even the slightest move away from this tight pH range and the body will compensate through many mechanisms to return the blood back to its normal pH values.

Blood alkalinity is primarily governed by the Hendersen-Hasslebach equation [H-H], which states that the pH is regulated by the relationship between the presence of carbon dioxide, PCO2, and bicarbonate concentration [HCO3-].

pH = [HCO3]- / CO2

 Alterations in bicarbonate levels are controlled by the kidneys. They are slow reactions, ranging from 8 hours to 5 days, whereas breathing controls levels of carbon dioxide. These reactions have an immediate effect, within seconds.

pH scale

Unfortunately, when it comes to pH regulation many people only look at one half of the equation. This is simply because of their schooling and development as a health practitioner. Most health courses are taught from the Hippocratic idea that food is medicine and all disease starts in the gut.  This viewpoint means that regulation of pH is observed from a kidney and bicarbonate perspective only (ie. One half of the H-H equation). The “kidney only” perspective brings with it two problems:

A.      Nutrition, as complex as it is, can be reduced to the simplicity of being alkaline or acidic.

With this ideology now comes the bandwagon of nutrition guru’s and vegans who rave about the alkalinity of vegetables and how ”bad” red meat is because it is too acidic. The noise created by such dogma’s drowns out the benefits of quality red meat like our need for cartnitine, B12, Iron and amino acids for health.

B.      Breathing is only considered to have a reflexive compensatory role to play in balancing blood aklainity.

 We eat acidic food or exercise hard and we generate acids in our body. Our body’s only compensatory mechanism reacts to this accumulation of acid is to ventilate (breathe) more frequently to balance the body.

But did we ever stop to consider what would happen to our blood pH if our breathing patterns were off?

Or if we were able to prime our system for higher acid loads by supra-ventilating prior to a big workout?

Or if we were able to alter our breathing patterns, post-workout, to restore blood pH values more quickly than just sitting down and having a post-workout shake?

Think about it.

Respiratory physiologists know that the lungs excrete x100 times more acids than the kidneys

per milli-equivalent.

This means the lungs are a better regulator of acid ‘in the moment’ than the kidneys. So,

doesn’t it make sense that CO2 is a very powerful regulator of blood alkalinity.


 if our breathing patterns are dysfunctional

 if we have a low CO2 tolerance level

If we have a high ‘acid-forming’ life due to poor nutrition & lots of exercise


We may have ingrained a poor breathing pattern into our body with the result that the kidneys have to work hard over time to compensate and our blood ph, even though it looks healthy, is managed by compensatory mechanisms.

Over time, the body will break down because of the chronic mismanagement of our breathing, the overburden to the kidneys and a lifestyle that doesn’t suit our bodies.


We develop a lower tolerance to exercise.

We have more pain post workout.

We lose balance and co-ordination.

We have lower attention spans.

We develop performance fear and anxiety.

And so, as Peter Litchfield stated in his paper “Good Breathing, Bad Breathing” the H-H equation could be rewritten as:

physiology / behaviour

Where our behaviour (breathing) impacts our physiology (blood pH) and our blood alkalinity can impact our behaviour.


This gives CO2 regulation a critical role in balancing blood alkalinity.

When we understand the H-H equation from this health perspective, we begin to understand the vital role that breathing and CO2 plays in balancing pH levels.

“The transport of CO2 has a profound effect on the acid-base status of the blood and the body as a whole”.

 John West & Andrew Luks (2016). West’s Respiratory Physiology Book

Now what do I do?

That’s great Leo Daniel. So now I know a little more about CO2 in the body. How can I use that information to empower myself?

Simple,  You have three choices:

  1. You can continue your research,

  2.  Start experimenting yourself or

  3. Dive deeper into breathing by partaking in our on-line course.

If you want to continue your research, I suggest you go back to my archive and begin with this article on the relationship between stress and breathing. It will show you how your life is impacting your breath patterns and your health.

If you’re more interested with experimenting with your breath, start with this article on nose breathing and you will begin to notice the profound benefits of filtering air and retaining CO2 in your body just by switching your breathing vent.

And if you feel like you’d like to start diving deep into breath practice, then I suggest you begin with the Breathe: 1st Princples program. It will coach you the foundations of healthy breathing for sport and life.



West, J.B. & Luks, A.M. (2016) West’s Respiratory Physiology. The Essentials. 10th ed. Wolters Kluwer

Litchfield, P., (2006). “Good Breathing, Bad Breathing”.

Kolb, P., (2001). Summary of Buteyko’s Theory on Asthma.

Lum, L.C., (1975). “Hyperventilation: The Tip And The Iceberg”. Journal of Psychosomatic Research, 19: 375 – 383. Pergamon Press

Leo Daniel Ryan

For 10 years I have dedicated my professional life to coaching clients and personal trainers to achieve their goals. I have worked at the highest levels of industry in both Ireland and Canada.