How do you do a physiological sigh?

  1. Sit in a chair or lie down.
  2. Breathe in slowly through your nose until your lungs feel full.
  3. Without breathing out, take one more short breath in through your nose to top up. It is normal for this second breath to be small.
  4. Breathe out slowly through your mouth, all the way, until your lungs feel empty.
  5. Repeat at an easy pace. In the study described below, people did this for 5 minutes.

If you prefer, you can breathe out through your nose too. Keep it gentle: the breath out should be long, not forced. If you feel faint or unwell, stop and breathe normally.

What is the difference between a sigh and cyclic sighing?

One physiological sigh is a single double-inhale and long exhale. Cyclic sighing means repeating that pattern for several minutes as a practice. The name comes from research by Balban and colleagues, which tested cyclic sighing against other breathing methods.

What did the research on cyclic sighing find?

The main study is a 2023 randomized trial in Cell Reports Medicine. Here is what it did and found, in plain terms:

  • 108 adults practised for 5 minutes a day for about a month, at home. They were split into cyclic sighing (30 people), box breathing, a fast breathing method, or mindfulness meditation.
  • Every group felt better after their daily practice: more positive mood and less anxiety.
  • Cyclic sighing showed the largest daily rise in positive mood, and the largest drop in breathing rate at rest. Both were significantly greater than with mindfulness meditation.
  • The authors point to the two features that set it apart: the long exhale and the double inhale.

Keep the limits in mind. It was a small study run remotely during the pandemic. The authors describe it as exploratory and note they could not check exactly how people practised. People with serious medical or psychiatric conditions were not included. It shows promise for everyday stress. It does not show that sighing treats anything.

When might a physiological sigh help?

Because it takes only a few breaths, people use it in small moments: before a hard conversation, after reading a stressful message, or when they notice they are holding their breath. A few minutes of cyclic sighing is closer to what the study tested.

If you want a slow breath with no double inhale, try calm breathing (4 in, 6 out). It keeps the same idea of a breath out that is longer than the breath in.

Try it with Bliss

In CalmSpace.ai, Sigh is one of the five rhythms in Breathe together: in for 2 seconds, a little more for 1, then out for 6. Host a session, send the link, and up to 6 people breathe in time, wherever they are. Bliss can guide everyone with her voice. Pick 1, 3, 5 or 10 minutes; 5 minutes matches the study. Hosting is free: sign up at app.calmspace.ai.

More guides: resonant breathing, breathing together from far away, all breathing guides.

Frequently asked questions

How long should I do cyclic sighing?

The 2023 study by Balban and colleagues used 5 minutes a day. A single sigh or two takes only a few seconds, but the study tested the 5-minute practice.

Should I breathe through my nose or mouth?

In the study, people were asked to take both breaths in through the nose and breathe out through the mouth, but breathing only through the nose was allowed too.

Is the physiological sigh better than box breathing?

In one small 2023 study, cyclic sighing showed the clearest improvement in mood and the biggest drop in resting breathing rate, compared with mindfulness meditation. All the methods tested helped mood. More research is needed.

Why is the second breath in so short?

It only tops up lungs that are already nearly full. The study told people it is normal for the second breath to be shorter and smaller than the first.