Box breathing: four counts to a slower pulse

Something odd about the autonomic nervous system: you cannot control your heart rate, your digestion, or whether you sweat. But you can control your breath — and the breath runs straight into all of those.

How to do it

• Breathe in through the nose for a count of four.
• Hold for four.
• Breathe out through the mouth for four.
• Hold empty for four. Then repeat.

Four cycles is enough to feel a difference. The name comes from the four equal sides of a box, and the pattern is trained in the military because it is simple enough that people can still do it while frightened.

Why it works

The vagus nerve runs from the brain down through the chest and abdomen, and it is the main channel for the resting state. A slow exhale stimulates it and slows the heart. That is why the out-breath matters more than the in-breath — if you remember only one thing here, make it lengthen the exhale.

This is quite different from the advice to take a deep breath that people offer when you are tense. Deep and fast pushes you toward arousal, not calm. What settles you is the slow rhythm and the long exhale, not the volume of air.

The breath is the one place where conscious control reaches the autonomic nervous system.

When to use it

It is most useful not once you are already panicking, but in the two minutes before something you know will be tense: before walking into the meeting, before dialling the difficult call, before talking to your child at the end of a bad day.

It also works when sleep will not come. There, drop the empty hold and make the exhale twice the inhale: in for four, out for eight. The structure gives the mind something to count, and the rhythm gives the body permission to slow.

One honest caveat: stop if you feel lightheaded, and if you have a heart or respiratory condition, ask a doctor before practising breath holds. This is a gentle exercise, but gentle does not mean right for everyone.