Ask someone what carbon dioxide does in the body, and you'll probably hear the same answer: "It's a waste gas that we breathe out."
That idea has been repeated for decades, yet it only tells part of the story.
Carbon dioxide (CO₂) is one of the most important gases involved in human performance, energy production, and even the way your brain functions. Every breath you take is part of a finely balanced system where oxygen and carbon dioxide work together. When that balance is disrupted, your body pays the price.
Most people focus entirely on getting more oxygen. Athletes buy oxygen masks, fitness watches measure blood oxygen saturation, and many people assume that taking bigger, deeper breaths will solve fatigue or improve performance.
The truth is far more interesting.
Under normal conditions, your blood is already carrying around 97–99% of the oxygen it can hold. Unless you're at high altitude or have a medical condition affecting your lungs, breathing harder doesn't load much more oxygen into your bloodstream.
The real question isn't whether oxygen reaches your blood.
It's whether it reaches your muscles, organs, and brain.
This is where carbon dioxide becomes the star of the show.
The Bohr Effect
Over a hundred years ago, Danish physiologist Christian Bohr discovered something remarkable.
Haemoglobin, the protein inside your red blood cells that carries oxygen, doesn't simply release oxygen whenever it arrives somewhere in the body. It responds to the environment around it.
When carbon dioxide levels are higher, haemoglobin loosens its grip on oxygen, allowing it to leave the bloodstream and enter the tissues where it's needed most.
Imagine a delivery driver carrying parcels. Reaching the correct address doesn't guarantee the parcels will be delivered. Someone has to open the door.
Carbon dioxide is one of the signals that tells haemoglobin it's time to unload its oxygen cargo.
Without enough CO₂, oxygen can remain attached to haemoglobin for longer than it should. Blood oxygen levels may look excellent on a pulse oximeter, yet the cells receiving that blood can still experience an oxygen shortage.
This explains why some people feel tired, mentally foggy, or short of breath despite having perfectly normal oxygen saturation.
When We Breathe Too Much
Many people unknowingly breathe more than their body actually requires.
Stress, anxiety, constant talking, poor posture, mouth breathing, and years of habitual over-breathing can all reduce carbon dioxide levels.
Because CO₂ leaves the body every time we exhale, breathing excessively washes it out faster than it can be produced.
Lower CO₂ means haemoglobin holds onto oxygen more tightly.
The oxygen is still there, but it doesn't leave the bloodstream as easily.
For athletes, this can mean muscles fatigue earlier than expected.
For office workers, it may show up as poor concentration, headaches, cold hands and feet, or a constant feeling of low energy.
Ironically, many people respond by taking even bigger breaths, which can make the cycle continue.
Carbon Dioxide Is Part of Efficient Breathing
Your body constantly produces carbon dioxide as a natural result of creating energy.
Healthy breathing doesn't eliminate as much CO₂ as possible. Instead, it maintains enough of it to support efficient oxygen delivery throughout the body.
This is one reason many breathing methods encourage slower, quieter nasal breathing rather than large, visible chest breaths.
Nasal breathing naturally helps regulate ventilation, allowing carbon dioxide levels to remain within a healthy range. Over time, this can improve oxygen delivery, exercise tolerance, and recovery while helping calm the nervous system.
Looking at Breathing Differently
For years, breathing has been viewed mainly as a way of taking oxygen in and pushing carbon dioxide out.
Human physiology tells a more complete story.
Oxygen fuels your cells.
Carbon dioxide helps oxygen reach them.
Neither gas does its job well without the other.
The next time you notice yourself taking repeated deep breaths because you're feeling stressed or tired, remember that bigger breaths aren't always better breaths. Often, the body performs best when breathing is quiet, relaxed, and efficient.
Sometimes the smallest changes in the way we breathe have the biggest impact on how we feel.
If this has made you curious about your own breathing, I'd love to show you how to put these principles into practice. On 8 August, I'm running a live online breathwork class where you'll learn simple techniques to improve your breathing efficiency, increase your tolerance to carbon dioxide, and help your body deliver oxygen more effectively. Whether you're an athlete looking to improve performance or simply want more energy, better focus, and a calmer nervous system, you'll leave with practical tools you can use every day. I'd love to have you join us
If you'd like to build a regular breathing practice at your own pace, you're welcome to join my Patreon community. You'll find a growing library of guided breathwork sessions, meditations, educational videos, and exclusive content that isn't available anywhere else. New classes are added regularly, so you'll always have something to support your training, recovery, and nervous system health whenever it suits you.
See you next time,
Tamara
https://innerpowerlab.coach
