Box breathing, 4-7-8 breathing and the physiological sigh are three simple breathing techniques for calming the body. Box breathing uses four equal counts of breathing in, holding, breathing out and holding. The 4-7-8 breath, popularised by Dr Andrew Weil, breathes in for four, holds for seven and breathes out for eight. The physiological sigh, or cyclic sighing, is a double in-breath through the nose followed by a long out-breath. All three slow the breath, and the two exhale-focused methods emphasise a long breath out.
Last updated: 5 November 2026
Reading time: about 8 minutes
How we wrote this article: this article was written by Saj Ali. It compares three popular breathing techniques using published research, and every research claim links to its source.
Three breathing techniques in brief
- Box breathing. In 4, hold 4, out 4, hold 4. Steady and focusing.
- 4-7-8. In 4, hold 7, out 8. Popular before sleep.
- Physiological sigh. Two breaths in through the nose, one long breath out. Quick to calm.
- Research. In a Stanford trial, all breathing methods helped, and cyclic sighing gave the biggest mood boost.
- Best start. Five minutes a day of whichever you enjoy most.
Contents
- Why Breathing Techniques Work
- Box Breathing
- 4-7-8 Breathing
- The Physiological Sigh (Cyclic Sighing)
- What the Stanford Trial Found
- Side by Side
- Which Should You Choose?
- Tips for Comfortable Practice
- Going Further
- Frequently Asked Questions
- Key Takeaways
- Explore More on Self Help Supermarket
- Sources
Why Breathing Techniques Work
Your breath is one of the few parts of your nervous system you can control directly. Slowing it down, and especially lengthening the out-breath, supports the calming “rest and digest” side of your nervous system. A systematic review found that slow breathing was linked with greater heart rate variability and feelings of relaxation, comfort and alertness, alongside lower anxiety (Zaccaro et al., 2018). A meta-analysis of slow-breathing studies confirmed that it increases vagally mediated heart rate variability, a marker of a relaxed, flexible nervous system (Laborde et al., 2022).
Box Breathing
Box breathing, also called square breathing, gives equal time to four stages, like the four sides of a square.
- Breathe in through your nose for a count of four.
- Hold your breath gently for four.
- Breathe out slowly for four.
- Hold again for four, then repeat for a few minutes.
The even rhythm makes it easy to remember and gives the mind something to focus on, which many people find helpful before a meeting, presentation or exam.
4-7-8 Breathing
The 4-7-8 breath, which Dr Andrew Weil calls the “Relaxing Breath”, is described on his website as a simple exercise that takes almost no time and can be done anywhere (Dr Andrew Weil: 4-7-8 Breath). His instructions are:
- Place the tip of your tongue on the ridge just behind your upper front teeth.
- Breathe out completely through your mouth with a whoosh sound.
- Close your mouth and breathe in quietly through your nose for four.
- Hold your breath for seven.
- Breathe out completely through your mouth, with a whoosh, for eight.
- Repeat for a total of four breaths.
Weil notes that the ratio matters more than the exact timing, so you can count faster if holding feels hard (Dr Andrew Weil: 4-7-8 Breath). In a small study of 43 young adults, a short session of 4-7-8 breathing was followed by a lower heart rate and lower systolic blood pressure (Vierra et al., 2022).
The Physiological Sigh (Cyclic Sighing)
The physiological sigh is something your body does naturally, for example when you sigh deeply or settle after crying. Neuroscientist Andrew Huberman helped make the deliberate version popular. Done repeatedly, it is called cyclic sighing.
- Breathe in through your nose.
- When your lungs are nearly full, take a second short sip of air through your nose.
- Let it all go in a long, slow breath out through your mouth.
- Use one to three sighs to settle quickly, or repeat for up to five minutes.
What the Stanford Trial Found
In a randomised study from Stanford University, people practised one of three five-minute breathing exercises, or mindfulness meditation, every day for a month. The breathing groups did cyclic sighing, box breathing, or cyclic hyperventilation with breath holds (Balban et al., 2023).
Breathwork overall, and especially exhale-focused cyclic sighing, produced a greater improvement in mood and a greater reduction in breathing rate than mindfulness meditation. The authors concluded that daily five-minute cyclic sighing shows promise as a stress management exercise (Balban et al., 2023). Box breathing was one of the breathing methods in the trial; 4-7-8 breathing was not included.
Side by Side
| Box breathing | 4-7-8 | Physiological sigh | |
|---|---|---|---|
| Pattern | In 4, hold 4, out 4, hold 4 | In 4, hold 7, out 8 | Double in-breath, long out-breath |
| Breath holds | Yes, two | Yes, one long hold | No |
| Out-breath | Equal to in-breath | Twice as long as in-breath | Long and slow |
| Time needed | 2 to 5 minutes | About four breaths | 1 to 3 sighs, or up to 5 minutes |
| Often used for | Focus and steadiness | Winding down and sleep | Quick calm during the day |
| Research | Included in Stanford trial | Small physiology studies | Largest mood benefit in Stanford trial |
Which Should You Choose?
- For quick calm in the moment: one to three physiological sighs.
- For focus before a challenge: box breathing for two to five minutes.
- For winding down at night: four rounds of 4-7-8 in bed. See our Sleep guide for more.
- For a daily habit: five minutes of cyclic sighing, based on the Stanford results.
- For anxious moments: any exhale-focused method; our Anxiety and Panic Attacks pages have more ideas.
The best technique is the one you will actually use. Many people keep the sigh for daytime and 4-7-8 for bedtime.
Tips for Comfortable Practice
- Breathe gently. If you feel light-headed, return to normal breathing.
- If breath holds feel uncomfortable, shorten them or choose the physiological sigh, which has none.
- Sit or lie comfortably with relaxed shoulders.
- Practise when calm first, so the technique is familiar when you need it.
- If you are pregnant or have a heart or lung condition, ask your doctor which techniques suit you.
Going Further
For more breathing exercises, including humming bee breath, see our Breathing page. Our Breathwork guide covers wider methods, the Breathwork hub gathers videos and apps, and Nervous System Regulation and How to Lower Cortisol Naturally show how breathing fits with sleep, movement and rest.
Frequently Asked Questions
Which breathing technique is best for anxiety?
Exhale-focused techniques such as the physiological sigh and 4-7-8 are popular. In a Stanford trial, cyclic sighing gave the largest improvement in mood.
What is the difference between box breathing and 4-7-8?
Box breathing uses four equal counts of four. The 4-7-8 breath has a longer hold and an out-breath twice as long as the in-breath.
How do you do a physiological sigh?
Breathe in through your nose, take a second short sip of air, then breathe out slowly and fully through your mouth.
Who created 4-7-8 breathing?
It was popularised by Dr Andrew Weil, who calls it the Relaxing Breath.
Does 4-7-8 breathing help you sleep?
Many people use it to wind down in bed. A small study found it lowered heart rate and systolic blood pressure.
How long should I practise breathing exercises?
About five minutes a day, as in the Stanford study, is a good start.
Can I do breathing exercises anywhere?
Yes. The physiological sigh in particular is quick and discreet.
Key Takeaways
- Box breathing uses four equal counts; 4-7-8 lengthens the hold and the out-breath; the physiological sigh is a double in-breath and long out-breath.
- Slow breathing is linked with higher heart rate variability and feeling calmer.
- In a Stanford trial, daily five-minute breathwork improved mood, with cyclic sighing giving the largest benefit.
- Box breathing suits focus, 4-7-8 suits bedtime, and the sigh suits quick calm.
- Breathe gently and skip holds if they feel uncomfortable.
- Five minutes a day is a good habit to build.
Explore More on Self Help Supermarket
Use these pages alongside this one:
- Breathing – calming breathing exercises
- Breathwork – the complete guide
- Anxiety – practical ways to feel calmer
- Panic Attacks – what helps in the moment
- Nervous System Regulation – calm your body and mind
- Meditation Music – choosing sounds that support your practice
- Browse all self-help techniques – compare every method on Self Help Supermarket.
Sources
- Zaccaro, A., Piarulli, A., Laurino, M., et al. (2018). How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, 353. https://doi.org/10.3389/fnhum.2018.00353
- Laborde, S., Allen, M. S., Borges, U., et al. (2022). Effects of voluntary slow breathing on heart rate and heart rate variability: a systematic review and a meta-analysis. Neuroscience and Biobehavioral Reviews, 138, 104711. https://doi.org/10.1016/j.neubiorev.2022.104711
- Weil, A. Breathing exercises: 4-7-8 breath. DrWeil.com. https://www.drweil.com/videos-features/videos/breathing-exercises-4-7-8-breath/
- Vierra, J., Boonla, O., and Prasertsri, P. (2022). Effects of sleep deprivation and 4-7-8 breathing control on heart rate variability, blood pressure, blood glucose, and endothelial function in healthy young adults. Physiological Reports, 10(13), e15389. https://doi.org/10.14814/phy2.15389
- Balban, M. Y., Neri, E., Kogon, M. M., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895. https://doi.org/10.1016/j.xcrm.2022.100895
Self Help Supermarket guides are for general information and are not a substitute for professional medical or psychological advice.