How to Use a CO2 Table for Dry-Land Breath-Hold Training

Before you start

Read the breath-hold safety rules. Train alone only on dry land, never in or beside water. Every in-water attempt requires a trained buddy.

Spearos, surfers and swimmers can see which table shape fits their goal.

The reason for the dry-land rule is shallow water blackout.

A CO2 table is a sequence of breath holds with a consistent hold duration and progressively shorter recovery periods. The name describes the session pattern; it does not guarantee a particular physiological adaptation or improvement time.

If you want the session rather than the reasoning, the CO2 table for beginners opens at a 60-second maximum on the Easy setting, and the CO2 table for freediving opens at 120 seconds on Classic.

New to breath-hold training

Breath-hold training is structured, repeatable practice with sub-maximal holds, done dry when you are alone. Its clearest effect is that the discomfort of a hold becomes familiar and easier to stay calm with.

During a hold two things run in parallel: oxygen falls gradually and carbon dioxide accumulates. A review of respiratory responses to a maximal apnoea describes the urge to breathe as multi-factorial, with rising carbon dioxide contributing substantially and falling oxygen, lung volume and respiratory-muscle activity also shaping when someone stops. Involuntary breathing movements commonly appear during longer holds; their timing and strength vary between people and between attempts, and they are not a gauge of blood oxygen. See breath-hold contractions.

Freedivers and spearfishers use tables alongside in-water instruction. Surfers and other water-sports athletes use dry practice to be calmer rather than panicked during an unplanned hold-down, which does not substitute for water rescue skills. Endurance and combat-sport athletes experiment with it, and that is where the sport literature sits: reviews of apnoea training and aerobic and anaerobic performance and of breath-holding in sports report possible benefits for some outcomes while calling for better-defined protocols.

You need no equipment and no experience. Record one controlled baseline attempt with the breath-hold timer first; it is planning input for your tables, not a score. Consult a doctor before starting if you have heart, lung, or neurological conditions, or are pregnant.

Build a starting table

Choose a dry-land hold duration you can repeat without a maximum effort. If you use a recent test, treat it as a reference rather than a target you must exceed.

The free CO2 table generator calculates a table from the time you enter. Review every round before starting and shorten the session if it looks too aggressive.

Follow the table

During each recovery interval, allow your breathing to return to a calm, normal rhythm. Start the next hold only if you feel steady. End the session if you feel faint, confused, unwell, or unable to recover normally.

The later rounds will usually feel different because the recovery periods are shorter. Discomfort is not a command to continue. Stop rather than forcing completion.

Adjust the next session

Keep a simple record of the table, whether you completed it, and how the last rounds felt. If several sessions feel manageable, change one variable: hold duration, recovery time, or number of rounds. Small changes make it easier to tell what altered the difficulty.

There is no evidence-backed universal rule that everyone should train a fixed number of times per week or improve by a set percentage. Leave recovery time between demanding sessions and reduce the load when you are ill, sleep-deprived, or unusually fatigued.

Understand what the table trains

During apnea, rising carbon dioxide contributes to respiratory drive, while oxygen, lung volume, and other signals also affect the breakpoint. Read CO2 tolerance explained for the physiology and limits of the term.

Research on apnea training is mixed and protocol-specific. A table may help someone practise repeatable dry-land holds, but it should not be sold as treatment for anxiety, sleep, cardiovascular disease, or another medical condition.

Continue with the right tool

• Generate a session with the CO2 table tool.
• Measure a dry-land attempt with the breath-hold timer.
• Review broader technique in how to hold your breath longer.
• Compare the apps that run these tables for you in best breath-hold apps in 2026.
• Skip the setup with the beginner CO2 table preset or the freediving CO2 table preset.