Free calculator
CO2 & O2 Table Calculator
Set your maximum breath hold and instantly see what your first two breath-hold training tables look like — round by round.
1:35
CO2 tablefirst
8 × 0:52 hold · the break shrinks from 1:30 to 0:20
O2 tablelater
Hold from 0:27 to 1:16 · the break stays at 2:00
The page calculates exactly like the Coach in the app does when you do a table for the first time.
Round by round
To copy down or take with you: the times for a maximum attempt of 1:35.
CO2 table
| Round | Hold | Breathe |
|---|---|---|
| 1 | 0:52 | 1:30 |
| 2 | 0:52 | 1:20 |
| 3 | 0:52 | 1:10 |
| 4 | 0:52 | 1:00 |
| 5 | 0:52 | 0:50 |
| 6 | 0:52 | 0:40 |
| 7 | 0:52 | 0:30 |
| 8 | 0:52 | 0:20 |
O2 table
| Round | Hold | Breathe |
|---|---|---|
| 1 | 0:27 | 2:00 |
| 2 | 0:34 | 2:00 |
| 3 | 0:41 | 2:00 |
| 4 | 0:48 | 2:00 |
| 5 | 0:55 | 2:00 |
| 6 | 1:02 | 2:00 |
| 7 | 1:09 | 2:00 |
| 8 | 1:16 | 2:00 |
What the two tables train
You hold your breath for the same time in all eight rounds — 55% of your maximum attempt. In between, the break gets 10 seconds shorter each round, from 1:30 down to 0:20.
The short breaks aren't enough to fully breathe off the CO2. You get used to the urge to breathe and learn to stay relaxed with it. This is the table you start with.
The break always stays at 2:00, but each hold gets longer, usually by 15 seconds. The last round is at 80% of your maximum attempt. With a short maximum, the step gets smaller so the first round doesn't end up too short.
It works closer to your limit. That's why it only comes in once you feel confident with the CO2 table.
How to train with them
- Two to three tables a week, never two on the same day.
- The two to three times a week apply to the tables. Calm breathing exercises without long holds are fine every day.
- Start with the CO2 table. Add the O2 table once the CO2 table feels comfortable.
- Ideally on an empty stomach, about two hours after your last big meal. Holding your breath is usually harder on a full stomach.
- In every round, stop while you still feel in control — then breathe calmly.
- Repeat your maximum attempt every one to two weeks, never on the same day as a table, and recalculate your tables afterwards.
Five rules, no exceptions
- Never train in or near water, and never alone in water.
- Only lying down or seated securely — never standing, never while driving.
- Don't hyperventilate. Breathe calmly and normally before every exercise.
- If you feel dizzy or unwell, stop at once and keep breathing normally.
- With pre-existing conditions or during pregnancy, check with a doctor first.
In the app, the Coach keeps calculating
Atmea sets up both tables for you, guides you through every round with voice cues and remembers how hard each one felt. After every maximum attempt, the Coach suggests new times — you decide whether to take them.
The app launches on iOS in October 2026. The Android version follows by November 2026.
This page gives general guidance for training on land. It does not replace medical advice. Atmea is a training tool, not a medical device.