Kumbhaka

Retention — holding the breath, deliberately, as part of a structured practice. The part of pranayama most often skipped in modern teaching, and the part the classical texts treat as the centre of the whole subject.

The two kinds

Antara kumbhaka — retention after the inhale. Lungs full. Stimulating.

Bahya kumbhaka — retention after the exhale. Lungs empty. Settling, and considerably more challenging psychologically.

There is also kevala kumbhaka, a spontaneous suspension of the breath that arises in deep practice rather than being performed. Not something to aim at directly.

What happens during a hold

Carbon dioxide rises. This is the main driver of everything else. The urge to breathe is triggered by rising CO₂, not by falling oxygen — a fact worth knowing, because it means the discomfort you feel during a hold is not a shortage of oxygen.

Tolerance to CO₂ improves with training. This is the primary measurable adaptation. Over months, the same hold produces less urgency, and resting breathing rate tends to fall.

Heart rate slows during a hold after the inhale, following an initial rise. There is a well-documented reflex involved here.

Attention becomes very simple. During a retention there is nothing else available. This is a large part of why the classical traditions valued it.

How to practise it

Prerequisites, and they are not optional:

• Several months of comfortable ratio work with no retention.
• A reliable seated posture you can hold without fidgeting.
• The ability to exhale completely and slowly.
• Jalandhara bandha, for anything beyond a few seconds.

The basic practice, after the inhale:

1. Sit up. Hips above knees, spine stacked. Empty stomach.
2. Exhale completely.
3. Inhale slowly over four counts. Not to maximum — to about eighty percent of full. A maximally full inhale creates pressure and makes the hold much harder.
4. Engage jalandhara bandha — sternum lifts, chin lowers.
5. Hold for two counts.
6. Release jalandhara.
7. Exhale slowly over six or eight counts.
8. Two or three normal breaths.
9. Repeat five times.

That is a complete first session. Two seconds. Not ten.

Building: add one count to the retention every week or two, provided the exhale after the hold is still smooth and unhurried. If the exhale comes out in a rush, the hold was too long.

A reasonable destination after a year is 4:8:8 — four in, eight held, eight out. The classical 1:4:2 with a sixteen-count hold is well beyond that and should be built with a teacher.

Retention after the exhale is introduced later and built more slowly. Two counts, and increase very gradually. It is harder because an empty-lung hold produces the urge to breathe faster.

The rules

Never hold to your limit. The retention should end while it is still comfortable. If you are fighting at the end, or the following inhale is a gasp, the count is too long. Reduce it.

The exhale after the hold is the test. It should be slow, controlled and even. If it is not, the hold was too long. This is a more reliable indicator than how the hold itself felt.

Never in water. Breath-hold practice near or in water is genuinely dangerous — shallow-water blackout kills people every year. This is not a caution, it is a rule.

Never while driving, or standing. Seated, on a floor, only.

Empty stomach. Two hours minimum.

Stop for the day if you get light-headed. Do not push through it.

What it builds

CO₂ tolerance, which shows up as a calmer, slower resting breath and less air hunger under exertion.

Diaphragm strength and control.

A specific quality of attention. During a retention there is no movement, no counting of the breath, and no external object. It is the closest thing in the physical practice to pure concentration.

Preparation for meditation. Every classical text puts retention before meditation in the sequence, on the grounds that a settled breath produces a settled mind. Whether or not you accept the framing, the observable version — that a few minutes of retention practice makes sitting still noticeably easier afterwards — is easy to verify on yourself.

When not to

This is the practice in the whole subject with the most serious contraindications. Do not practise retention if any of these apply, and ask someone qualified if you are unsure:

• Uncontrolled high or low blood pressure.
• Any heart condition.
• Epilepsy.
• Glaucoma or retinal problems.
• Pregnancy.
• Recent surgery, particularly abdominal, chest or eye.
• A history of panic attacks. Retention reliably produces air hunger, which is one of the more common panic triggers.
• Severe asthma, uncontrolled.

If any apply, work with ratio and rate instead. Extended-exhale breathing without retention delivers most of the settling effect and none of the risk.

Learning it

Of everything in pranayama, this is the practice most worth learning in person. Not because a written description is inadequate — the mechanics are simple — but because the judgement about how far to push is difficult to make on yourself, and a teacher who has watched a thousand people do this will see when your count has got ahead of your capacity.

If you are learning alone: be more conservative than you think necessary, build over months rather than weeks, and treat the quality of the exhale afterwards as your only measure of whether the hold was appropriate.