Nadi Shodhana

Alternate-nostril breathing. Described precisely, because it is usually taught with a vague hand-wave and people spend years doing a slightly wrong version.

What it is

You breathe in through one nostril, out through the other, in through that one, out through the first. One full cycle is four breaths' worth of movement through two nostrils. The airflow alternates; the count stays even.

Nadi means channel; shodhana means cleansing. The traditional account is that it balances the flow through the two main channels of the subtle body. The observable account is that it slows the breath, adds resistance, requires continuous attention to a hand position and a count, and reliably produces a settled, alert state after a few minutes. Both are worth knowing; only the second is checkable.

The hand

Right hand, traditionally, regardless of handedness.

Vishnu mudra: fold the index and middle fingers down into the palm. That leaves the thumb, ring finger and little finger.

• Thumb closes the right nostril.
• Ring finger (with the little finger resting alongside it) closes the left.

If folding two fingers down is awkward, rest them lightly on the forehead between the eyebrows instead. It makes no difference to the practice.

Where to press. On the soft part of the nostril, just below where the bone ends — roughly a centimetre above the nostril opening. Press inward and slightly back, enough to close it fully with no air passing. Not so hard that you distort the nose or feel pressure in the sinus.

Keep the elbow down and the shoulder relaxed. A common and quietly exhausting error is holding the elbow out to the side, which fatigues the shoulder in about three minutes and makes the whole thing feel like work.

Rest the left hand on the knee.

The sequence

Sit up, hips above knees, spine stacked. Take a few normal breaths first.

1. Close the right nostril with the thumb. Exhale fully through the left.

2. Inhale through the left.

3. Close the left with the ring finger, release the thumb. Exhale through the right.

4. Inhale through the right.

5. Close the right, release the ring finger. Exhale through the left.

Steps 2 to 5 are one round. Continue from step 2.

Note the pattern: you always exhale through the nostril you are about to inhale through — no. Read it again: you exhale through one, then inhale through the same one, then switch. Out left, in left, out right, in right. The switch happens after the inhale, not after the exhale.

Getting this backwards is the most common error and it produces a different practice. Out-in on one side, then switch.

Starting side

Start by exhaling through the left, and take the first inhale on the left.

The traditional reason involves the channels. The practical one: it is a convention that keeps the practice consistent, and consistency lets you notice changes. Pick it and keep it.

The count

Weeks one to three: equal. Four in, four out. Or five and five. No retention.

Weeks four onwards, if it is comfortable: lengthen the exhale. Four in, six out. Then four in, eight out.

Months in, and only if the above is easy: add retention after the inhale. Four in, four held, eight out. The classical 1:4:2 ratio — four in, sixteen held, eight out — is an advanced practice and not something to arrive at alone.

Never let the count become a strain. If the inhale after an exhale is desperate, the ratio is too long. Reduce it.

How long

Five minutes to begin, which is roughly ten to fifteen rounds at a moderate pace.

Ten minutes is a full practice. Twenty is plenty for anybody. Length is not the variable that matters; consistency is.

The two mistakes that make it uncomfortable

1. Breathing too deeply. People treat it as a deep-breathing exercise, take enormous breaths, and get light-headed within two minutes. The breath should be normal in volume and slow in rate. If you feel dizzy, you are over-breathing — stop, breathe normally for a minute, and restart with smaller breaths.

2. Pressing too hard, or in the wrong place. Pressing on the bony part does not close the nostril and pressing very hard causes a headache. Light pressure on the soft tissue is all it takes.

If one nostril is blocked

This is normal and it is not a problem with you. The nostrils alternate dominance through the day on a cycle of roughly one to two hours — at any given moment, one is usually more open than the other. It is called the nasal cycle and everyone has it.

If it is mild: proceed. The practice itself often evens it out within a few minutes.

If one side is genuinely blocked: lie on your side with the blocked nostril upward for a few minutes before you start. That usually opens it.

If you have a cold or persistent congestion: do not do this practice. Do a long-exhale practice without the hand instead. Forcing air through a blocked nostril is unpleasant and pointless.

When to do it

Any time except immediately after eating. It is one of the few practices that works well both before a session and as a standalone.

Before asana: settles the attention and sets the breath.

After asana, before Savasana: a natural place for it.

Standalone, morning or evening: ten minutes.

Before sleep: with a long exhale ratio and no retention, it works well.

What to expect

First session: mostly you will be managing the hand and losing track of which side you are on. This is normal and passes within a week.

After a week or two: the mechanics become automatic and you start actually noticing the breath.

After a month: a distinct settled-but-alert state at the end of ten minutes. Not drowsy, not stimulated. This is the effect the practice is for, and it is quite specific once you know it.

When to be careful

Skip retention entirely, and ask someone qualified before practising, if you have uncontrolled blood pressure, a heart condition, epilepsy, or are pregnant. Without retention, in a normal volume, this is among the gentlest practices there is.