CO₂ table generator
Enter your current maximum breath hold and get a conventional CO2 table: the hold stays the same length, the rest between rounds gets shorter. Practise alone only on dry land.
Enter your best breath hold time. If you're unsure, try our breath hold timer first.
How to read the table
Every row is one round: a hold, then a rest. The hold stays at the same length the whole way down the table. The rest shrinks by a fixed amount each round until it reaches 10 seconds, then holds there. Because the hold never changes, the table gets harder only because you get less time to recover between rounds.
All three difficulties run 7 rounds. They differ in how long the hold is and how fast the rest disappears: Easy starts with the most recovery and takes it away slowly, Hard starts with the least and takes it away fastest. These are the same presets the BreathHold app uses, so a table you generate here matches the one the app builds from the same input.
The name describes the structure of the session. It does not measure carbon dioxide, and it does not guarantee a particular adaptation. Read the whole table before you start so you know what the last round asks of you.
Picking a starting time
The generator sets the hold at 40, 50, or 60 percent of your maximum depending on the difficulty you pick. Enter a maximum you have actually reached while relaxed and seated, not a personal best from a single good attempt. If you are unsure, enter a lower number or start on Easy. A table that feels manageable in the last three rounds is a table you can repeat, and repetition is the point.
If you finish every round without strain, raise the input by 10 to 15 seconds next session rather than adding rounds. If you cannot complete the final two rounds, lower it.
Common mistakes
- Hyperventilating before a round. Breathing hard to extend a hold removes the urge to breathe without adding oxygen. Never do it. See the safety guide.
- Using the table in or near water. This is a dry-land session. A breath hold in water needs a trained buddy watching you, every time.
- Chasing the input number. Raising your entered maximum does not train anything. Completing the session you generated does.
- Running a table daily. Leave recovery days between sessions.
Where to go next
A CO2 table shortens rest while the hold stays fixed. An O2 table does the opposite: the rest stays fixed and the hold gets longer. The two train different parts of the same session, and the comparison between them covers when each one belongs in a week. For the reasoning behind the progression, read how to train CO2 tolerance, or generate the counterpart with the O2 table generator.