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CO2 and O2 tables
Two simple training structures do most of the work in apnea. One trains your tolerance to the urge to breathe, the other your oxygen economy. Here is how each works.
If you want to hold your breath longer, testing your max over and over is the slow way to do it. The fast way is structured training, and almost all of it runs on two simple formats: CO2 tables and O2 tables. They look similar on paper and train completely different things. This guide is part of the breath-hold training guide.
Dry land only. Do these sitting or lying down, never in or near water, and never after hyperventilating. The safety rules in the main guide apply to everything here.
#CO2 tables: tolerance to the urge to breathe
A CO2 table is a set of holds of the same length, with the rest between them shrinking each round. Because each rest is shorter, your body clears less carbon dioxide between holds, so CO2 keeps climbing. You are deliberately training the one thing that stops most people: the ability to stay relaxed as the urge to breathe grows.
CO2 tables are the bigger win for beginners, because early on your limit is almost always tolerance, not oxygen. They also feel manageable: the holds are never near your max, only the rising discomfort makes them harder as you go.
Here is what a CO2 table looks like, with a fixed hold and shrinking rests:
| Round | Rest | Hold |
|---|---|---|
| 1 | 1:45 | 1:00 |
| 2 | 1:30 | 1:00 |
| 3 | 1:15 | 1:00 |
| 4 | 1:00 | 1:00 |
| 5 | 0:45 | 1:00 |
| 6 | 0:30 | 1:00 |
The hold stays comfortable. It is the shrinking recovery that makes the later rounds bite.
#O2 tables: oxygen economy
An O2 table is the mirror image: the rest stays long and full, while the holds grow longer each round. With full recovery every time, CO2 is not the challenge. Instead you are pushing gently toward lower oxygen, teaching your body to function calmly with less, and reinforcing the dive reflex.
O2 tables are more demanding and belong a bit later in your progression, once CO2 tables feel comfortable. A simple shape:
| Round | Hold | Rest |
|---|---|---|
| 1 | 1:00 | 2:00 |
| 2 | 1:15 | 2:00 |
| 3 | 1:30 | 2:00 |
| 4 | 1:45 | 2:00 |
| 5 | 2:00 | 2:00 |
#Why you scale tables to your own max
The numbers above are illustrations, not a prescription. The single most important rule is that a table must be built from your breath-hold, not someone else's. A one-minute hold might be easy for one person and near-max for another, and a table that ignores that is either useless or unsafe.
The clean way to do it is to base every hold and rest on a percentage of your current maximum. That keeps the effort in the right zone as you improve, and it is exactly what Resonance does automatically, so you never have to copy numbers off the internet or guess.
#How to use them
- Two to three sessions a week, on dry land, with rest days between.
- Do not stack a hard CO2 table and a hard O2 table on the same day. Alternate them, or keep one light.
- Warm up with a couple of minutes of slow, relaxed breathing first. A little coherent breathing sets a calm baseline.
- Relax through every hold. Tables train the mind as much as the body. If you fight the holds, you lose the benefit.
- Stop if anything feels wrong. Lightheadedness, tingling or real distress means end the session. Progress is gradual.
#Common mistakes
- Making holds too long. CO2 tables work with comfortable holds, not maximal ones. The difficulty should come from the rests, not the hold length.
- Skipping recovery days. Apnea training needs rest like any other training. Daily hard tables stall progress.
- Copying a table from a video. Without scaling to your max, the numbers are meaningless for you.
- Hyperventilating to make it easier. Never. It removes the safety signal, not the risk.
Track whether it is all working with the BOLT score, a simple marker of CO2 tolerance that should rise over the weeks. And if you are just starting out, ease in with the static apnea guide for beginners.