Short answer
A physiological sigh is two inhales through the nose, one full breath and one short top-up, followed by a long, slow exhale through the mouth. For sleep, do three to five slow sighs as you lie down, keeping the exhale longer than both inhales. A 2023 study linked daily cyclic sighing with better mood and a lower resting breathing rate.
Key takeaways
- Double inhale through the nose, then a long exhale through the mouth.
- A handful of sighs can be enough to notice a shift. Keep the exhale unhurried.
- The best evidence comes from a daytime stress study, so think of it as a wind-down tool, not a sleep switch.
On this page
The double inhale, step by step
You already do this without thinking. People sigh spontaneously throughout the day and during sleep, and the pattern helps reopen small air sacs in the lungs. Doing it on purpose, slowly, turns it into a calming exercise.
- Breathe in through your nose until your lungs feel comfortably full.
- Without breathing out, take a second, shorter sip of air through your nose to top up.
- Breathe out slowly through your mouth until your lungs feel empty. Make the exhale clearly longer than both inhales together.
- Repeat for one to five minutes, or for as long as it feels easy.
Keep the volume moderate. You are aiming for a soft, full breath, not a gasp.
The second inhale is small. If you cannot fit more air in, that is fine; even a tiny top-up counts. The long exhale afterward is what most people notice.
What the cyclic sighing study found
In 2023, researchers at Stanford published a randomized study in Cell Reports Medicine comparing five minutes a day of three breathing practices with mindfulness meditation over a month. The breathing groups were cyclic sighing, box breathing and cyclic hyperventilation.
All of the breathwork groups reported better mood than the meditation group, and cyclic sighing, the deliberate version of the physiological sigh, showed the largest improvement in positive feelings and a reduction in resting breathing rate. The participants practiced during the day, and the study did not measure sleep. Still, the finding that an exhale-heavy pattern lowers arousal is exactly why many people reach for it at bedtime.
How Soften Sleep fits in
Soften offers three breathing techniques to choose from: Soften Sigh, 4-7-8 Breathing and Box Breathing. Partner-Safe Mode keeps the experience more discreet at night.
Using it at bedtime and in the middle of the night
The sigh is short, so it works well as an opener. Try three to five slow sighs as soon as you lie down, then either keep going or move into a counted pattern such as 4-7-8 breathing once your breathing has slowed.
If you wake at night with your heart going, a few sighs are a low-effort first move that does not require deciding anything. Keep your eyes closed and the screen off. If a worry is driving the wake-up, follow the breathing with something that occupies your attention, like the cognitive shuffle, instead of trying to argue with the thought.
Exhaling through pursed lips makes the out-breath naturally longer and quieter. It is a good option if you share a bed and do not want an audible sigh.
When it is not the right tool
If you feel lightheaded, take smaller inhales and pause between sighs. Some people find any deliberate breathing makes them more aware of their breath and more alert. If that is you, skip breathing work and go straight to a neutral attention exercise.
Repeated nights of poor sleep deserve a conversation with a clinician, especially if you also have breathing problems while asleep, such as loud snoring with gasping. A bedtime exercise is not a substitute for that check.
Sources
- Balban, M. Y., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine. doi.org
Soften Sleep is a wellness tool designed to promote relaxation and help manage occasional sleeplessness. It is not a medical device and is not intended to diagnose, treat, cure, or prevent insomnia or any medical sleep disorder. If you are experiencing chronic sleep issues, please consult a qualified healthcare provider.
FAQ
How many physiological sighs should I do to fall asleep?
There is no fixed number. Start with three to five slow sighs and continue for a few minutes if it feels calming.
Is the physiological sigh the same as cyclic sighing?
Cyclic sighing is the deliberate, repeated version of the physiological sigh that researchers studied. The breath itself is the same double inhale and long exhale.
Should the exhale go through the mouth?
A mouth exhale makes it easier to lengthen the out-breath. Pursed lips keep it quiet if someone is asleep next to you.
Want this as a one-tap rescue?
Soften Sleep keeps quiet breathing and word prompts ready on your iPhone for the next time you wake up.