How to Increase CO2 Tolerance for Surfers (and Hold Your Breath Longer in the Ocean)

Improving CO2 tolerance for surfers can help you stay calm during wipeouts, recover faster, and handle longer hold-downs in the ocean.

If you surf long enough, you will face a moment where your breath really matters.

Maybe it’s a long hold-down on a big day.
Maybe you wipe out and get worked by a set.
Maybe you’re paddling hard to clear the break and you feel totally gased.

That burning feeling in your chest?
That fatigue setting in?
That panic rising up?

That’s not a lack of oxygen.
That’s a buildup of CO₂.

Learning how to increase your CO₂ tolerance can make you a calmer, safer, and more confident surfer. It’s one of the biggest secrets used by freedivers, big wave surfers, and water athletes around the world.

Let’s break it down in simple terms for regular surfers like you and I.

What Is CO2 Tolerance For Surfers?

CO₂ is carbon dioxide. Your body makes it every time you breathe.

Most people think they need to breathe because they are “out of oxygen.”
That’s not true.

You breathe because CO₂ builds up in your bloodstream.

When CO₂ gets high, your brain says:
“Breathe now, right NOW!”

So, when you’re underwater after a wipeout, the urge to breathe is caused by CO₂, not oxygen.

Why is that an important distinction? Because CO₂ tolerance is a skill, not a talent. And like all skills, it can be learned and improved with practice.

CO₂ tolerance denotes:

• How comfortable you are when CO₂ rises
• How calm you stay when your body wants air
• How long you can stay relaxed before panic sets in

Higher CO₂ tolerance = calmer hold-downs, more confidence and better surfing performance.

Why CO2 Tolerance for Surfers Matters

Improving CO₂ tolerance helps surfers:

• Stay calm during wipeouts
• Handle long hold-downs
• Recover faster between waves
• Paddle harder without burning out
• Surf bigger waves with more confidence
• Reduce panic in heavy wipeouts

Freedivers train CO₂ tolerance on purpose because it allows them to stay relaxed underwater and hold their breath for longer. Surfers can use the same tools, just in a safer and simpler way.

The Biggest Mistake Surfers Make with Breathing

Many surfers try to “take more air” before a wave.

They will often:

• Hyperventilate
• Take fast, big breaths
• Panic breathe after wipeouts

This might actually make things worse.

How?

Because fast breathing lowers CO₂ too much. When CO₂ rises again (which it always does), it rises faster and stronger, creating panic.

The goal should not be more air.
The goal should be better control.

How Freedivers Train CO₂ Tolerance (Simplified)

Freedivers use special breathing exercises called CO₂ tables featured later in this article.

But don’t worry you don’t need to, nor should you start there.

The best places to start are:

• Slow diaphragmatic breathing
• Calm breath holds
• Learning to relax during discomfort

You can use gentle versions of these exercises to improve your CO₂ tolerance for surfing.

5 Simple Ways to Increase CO2 Tolerance for Surfers

1. Learn To Breathe With Your Diaphragm

Diaphragmatic breathing or belly breathing is the optimal method for breathing. However, very few people breathe this way naturally.

This method refers to consciously using your diaphragm, which sits below your lungs, to draw your breath in and utilize the full volume of your lungs. It can be done in any position and during any activity.

However, to practice belly breathing:

• Assume a comfortable sitting or lying position
• Breathe deeply through your nose focusing on distending your belly rather than drawing into your upper chest
• Exhale through your nose or mouth
• Repeat for several minutes

2. Slow Your Breathing (On Land and in the Water)

Slow, diaphragmatic breathing is the foundation of CO₂ tolerance.

Try this exercise called Box Breathing:

• Breathe in through your nose for 4 seconds
• Hold your breath for 4 seconds
• Breathe out through your nose or mouth for 4 seconds
• Hold your breath for 4 seconds
• Repeat for several minutes

Practice this type of breathing:

• Several times everyday
• Before paddling out
• While sitting in the lineup
• After a wipeout

Slow breathing tells your nervous system that you are safe and that your system can relax.

3. Nose Breathing While Paddling

This is a powerful surfer trick.

When possible, paddle while breathing only through your nose.

Benefits:

• Builds CO₂ tolerance naturally by slowing the intake and expulsion of air
• Improves endurance
• Keeps your heart rate lower
• Trains a calm demeanor under effort

Start on small days.
If you need to mouth breathe, that’s okay — just return to the nose when you can.

4. Short, Relaxed Breath Holds (Dry Practice)

You do NOT need to push yourself.

Try this simple drill:

1. Sit or lie down
2. Take 3 slow breaths
3. Exhale normally
4. Hold your breath for 10–20 seconds
5. Breathe normally again

Repeat 3–5 times increasing the breath hold period to only mild discomfort.

The goal is not time.
The goal is relaxation.

This teaches your body that CO₂ discomfort is not dangerous.

5. Learn to Relax During Time Underwater

When systemic CO₂ levels rise, your body may:

• Tighten your chest
• Clench your jaw
• Speed up your thoughts
• Make you feel you need to struggle to the surface for air

Instead, practice the opposite when you’re underwater:

• Relaxing your face
• Dropping your shoulders
• Letting the water move you without resistance
• Return to the surface slowly and calmly

Most wipeouts that aren’t in really big surf last less than 20 seconds and a large portion of those less than 10 seconds.

Try a 20 second breath hold right now.
Pretty easy, right?
And it can be that easy in the water, with some practice.

A common freedivers mantra is:
“Relax into the urge.”

Surfers who stay loose, calm & relaxed last longer underwater.

6. Improve Recovery Breathing After Waves

After a wave or wipeout, try not to gasp for air as soon as you hit the surface.

Instead try this:

• Quick inhale through the nose (or mouth if your nose is blocked)
• Long, slow exhale through the mouth with your cheeks puffed
• Repeat 2–3 times as you collect your board

This helps clear CO₂ and calm your nervous system faster than taking large gulping breaths.

Safety First (Very Important)

• Never practice breath holds in water alone, regardless of the depth
• Never push breath holds to dizziness
• These exercises should feel easy to moderate strain only
• CO₂ training is about learned calm, not suffering

Big wave surfers and freedivers train smart before they train extreme.

7. CO₂ Tables For Focused CO2 Tolerance For Surfers

CO₂ tables are not a critical exercise for surfers the way that pop-ups and paddle training are.

However, if you feel the desire to take your CO₂ tolerance training to the next level, CO₂ tables are a simple and effective way that freedivers do that.

And the great news is, you don’t need anything other than a timer and a comfortable space to lie down.

Below is a simple example of a CO₂ table. You can download your own PDF copy of this table here for free.

The process for using a CO₂ table is as follows:

• Lie down in a comfortable position and relax your body
• Diaphragmatic breathing for 2 mins
• Breath hold for 90 seconds (if you are unable to hold your breath for 90 sec substitute all the 90 sec periods with a lower time that represents only mild strain)
• Breathe for 1min 45sec
• Breath hold for 90 seconds (or your substitute timeframe)
• Breathe for 1min 30sec
• Breath hold for 90 seconds
• Continue for 6-8 rounds

You will notice that the breath hold time remains the constant and the ventilation timeframe is gradually reduced.

This exercise helps to improve your CO₂ by reducing recovery time, which allows for a little more CO₂ build up after each round.

The Big Takeaway for Surfers

You don’t need super lungs to surf better.

You need:

• Calm breathing
• Better CO₂ tolerance
• A relaxed mind under pressure

By training like freedivers and breathing like experienced surfers, you can:

• Stay calmer in heavy surf
• Recover faster
• Surf longer sessions
• Feel more confident in the ocean

The ocean rewards calm.

And calm starts with your breath.

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