O2 tables: The most misunderstood tool in freediving

You can’t just do random breathing exercises and expect magic. You need the right stimulus for the right adaptation. Let’s talk about O2 tables, probably the most name-dropped, least-understood training tool in freediving.

What O2 tables actually do

A standard O2 table (oxygen deprivation table) keeps your rest intervals more relaxed, while progressively increasing your breath-hold time. You might hold for 1:30, rest for 2:00, then 1:45, rest for 2:00, then 2:00, rest for 2:00-you get it. The rest stays the same. The work gets harder.

The goal? Train your body to tolerate lower oxygen levels. You’re not gasping for air because of CO2 buildup (that’s what CO2 tables train). You’re running out of gas in the tank. Your oxygen saturation drops, your body starts screaming for O2, and you’re teaching yourself to stay calm and functional when the tank hits empty.

This is hypoxic training. And here’s the thing-it’s not about toughness. It’s about physiological adaptation.

Why freedivers screw this up

Most freedivers treat O2 tables like a spiritual journey where they simply go and see how long they can suffer.

Wrong.

O2 tables are a precision tool. They’re not about maxing out every hold or proving something to yourself. The entire point is controlled exposure to low oxygen states. If you’re blacking out or pushing to 90% of your max every round, you’ve missed the plot. You’re just frying your nervous system and learning nothing useful. (This connects directly to The World Record Problem: Why Chasing Numbers Will Wreck Your Freediving-training isn’t testing.)

The adaptation happens in the accumulation across multiple holds at moderate intensity. Not in one heroic death march.

How to actually use them

Here’s what works:

1. Know your current max dry static. Let’s say it’s 3:00. Your O2 table holds should peak around 2:15-2:30. Not 2:55. This isn’t a personal best attempt.

2. Rest intervals matter. Make it long enough to recover and not be constrained by CO2. You can start with 2:00. Recovery quality determines training quality (this isn’t CrossFit. We’re not training you to recover badly).

3. Track the sensation, not just the time. How quickly do contractions start? When does the oxygen hunger kick in versus the CO2 discomfort? Your body is giving you data. Pay attention. Write it down after your session.

4. Don’t overdo them. O2 tables are taxing. They’re not daily practice. If you’re doing them constantly, you’re either not going hard enough or you’re overtraining. Neither ends well.

The Real Training Effect

When you train O2 tolerance properly, you’re teaching your body to:

• Maintain cognitive function at lower O2 saturation
• Stay relaxed when every instinct says panic
• Recognize the difference between “I’m uncomfortable” and “I’m actually in trouble”

They also improve your hemoglobin’s oxygen-carrying capacity over time and increase capillary density. But that takes months of consistent work, not one heroic session where you see stars.

Where Appneist comes in

This is exactly why following a real training plan matters. O2 tables aren’t something you improvise each session. With Appneist, you follow a structured progression that’s tailored to your current abilities, keeps your rest intervals consistent, and-most importantly-keeps you accountable to the plan instead of just pushing blindly or doing whatever feels tough that day.

You log your holds, follow the session plan in the app, and get real progression instead of random suffering.

Look, O2 tables work. But only if you use them correctly. Stop treating them like a pain cave. They’re a training protocol. Run the protocol. Trust the process. Let the adaptations come.