O2 Tables (Oxygen Tolerance Training)

How to do it

1. Know your current best breath-hold, measured lying down on dry land. You need it to size the table.
2. Set the table so the last, longest hold is no more than 80 percent of that best^[1].
3. Lie down on a bed, couch or floor, away from water. Breathe normally for a minute or two, never fast or deep.
4. Rest: breathe calmly and normally. The rest is the same length every round.
5. At the end of the rest, take one full, relaxed breath in and hold. Stay still and soft.
6. Breathe when the hold ends, or sooner if you need to. Take one or two easy recovery breaths.
7. Repeat. Each hold is a little longer than the last. Release early on any round, the last one included.
8. After the final hold, stay lying down and breathe normally for a minute or more before you stand.

Benefits

• Calm deep into a hold

  Round after round, you practice staying relaxed further into a long hold, and the later minutes feel quieter.

• Quiet, total focus

  Long, still holds leave room for nothing else. You finish clear-headed and focused.

• Progress you can see

  Spoon saves every hold you did, so you can compare sessions week by week.

What the research says

O2 tables are standard freediving dry training, and the Molchanovs school lists them among the key areas to train at home^[2].

The most direct test of the format is a 2024 study. Twenty-eight people new to breath-holding did maximal holds, a CO2 table and an O2 table in random order^[3]. Maximal holds lowered blood oxygen saturation by about 16 percent and the O2 table by about 8 percent, and the rise in carbon dioxide did not differ between them. The authors suggest beginners focus mainly on maximal holds^[3].

Longer-term changes are real but slow. Trained breath-hold divers show a stronger diving response than non-divers, mainly as a result of training^[4]. When 13 people did five static holds a day for 8 weeks, their spleen, a store of red blood cells that squeezes during long holds, grew from 241 to 299 mL on average. How much it contracted during a hold did not change^[5].

The evidence for O2 tables as a method is limited: they are a structured way to practice long holds, with real risk, not a proven shortcut.

O2 table vs CO2 table

• O2 table: the rest stays the same and the hold grows each round^[1]. You spend longer on one breath, so oxygen drops lower.
• CO2 table: the hold stays the same and the rest shrinks^[1]. Carbon dioxide builds, so you train comfort with the urge to breathe.
• Freedivers build a base with CO2 tables first, then add O2 tables. Never do both on the same day, and keep each to two or three sessions a week^[1].

How to size your O2 table

Your last hold is the starting hold plus one increase for every round after the first. At Spoon's default that is 1:00 plus seven steps of 15 seconds: 2:45. Keep it at or under 80 percent of your best^[1], so a 2:45 last hold fits only if your best is about 3:26 or longer. Spoon does not size the table from your best, so do this math before you start.

Tips

• Train CO2 tables for several weeks before you add O2 tables.
• Every few weeks, measure your best hold again, dry and lying down, and resize the table from it.
• If a round turns into a struggle, lower the starting hold or the increase next time.
• If you feel lightheaded after the last rounds, stay lying down longer. Never push through it.

Related exercises

• CO2 TablesSame hold every round, less rest each time. You learn to stay calm while the urge to breathe builds.
• Buteyko BreathingBreathe a little less, through your nose, and time a calm breath-hold to track your progress.
• Wim Hof BreathingThirty full breaths and one quiet hold leave you wide awake.