Physiological Sigh
Calm · Beginner · 5 rounds
Double inhale + long exhale. Fastest way to calm down.
Popularized by Stanford neuroscientist Dr. Andrew Huberman. The double inhale reinflates collapsed alveoli, maximising CO2 offload on the long exhale - the fastest known real-time stress-relief tool.
How to practice
- Inhale for 3 seconds (through the nose)
- Sip In for 1 seconds (through the nose)
- Exhale for 6 seconds (through the mouth)
Benefits
- Fastest stress relief
- Works in real-time
- Reduces cortisol
- Science-backed
When to practice
As needed - even one cycle helps. Perfect emergency calm-down.
About Physiological Sigh
The double inhale is a real reflex — the body does it spontaneously during sleep and after crying, and it reinflates alveoli that have collapsed. The second, smaller sip of air is what distinguishes it from any other long-exhale pattern, and it is the part that gets dropped.
Best for: Speed. This is the fastest thing on the site — one or two cycles is a usable dose, which means it works in the ten seconds before you speak, not just in a five-minute sit.
Why it works
Heart rate is not steady within a breath — it rises on the inhale and falls on the exhale, an effect called respiratory sinus arrhythmia. Weighting the breath towards the out-breath (6s out against 4s in) spends more of each cycle in the falling half, which is why a long exhale is the most reliable lever anyone has for bringing heart rate down on purpose. At roughly 6 breaths a minute this is slow enough for that effect to be worth having without being so slow that holding the pace becomes the effort.
What to expect
The first two or three rounds usually feel like the exhale runs out early. That settles as the breath finds the pace — resist the urge to force the last second of air out, and let the out-breath finish rather than pushing it. A full session as timed here runs 50s.
Common mistakes
- Emptying the lungs completely on the long exhale. Finish the 6s out-breath with a little air still in reserve. Squeezing to empty recruits the abdominal wall, which is effort — and effort is the thing the pattern is trying to remove.
- Breathing bigger rather than slower. The target is 6 breaths a minute, not maximum volume. Pulling in as much air as possible on a 4s inhale over-ventilates and produces the light-headedness people mistake for the technique working.
- Switching to mouth breathing when it gets hard. The nasal route is part of the dose — it warms, humidifies and adds resistance, which slows the breath on its own. If the nose cannot keep up, reduce the pace rather than opening the mouth.
How it compares
Equal Breathing is symmetrical — 5s in, 5s out, against exhale-weighted — 6s out against 4s in here. Both are rated beginner, so the choice is about which shape suits you. Read about Equal Breathing.
Questions
- How long should I practise Physiological Sigh for?
- A session as timed here is 5 rounds and runs 50s, at roughly 6 breaths a minute. As needed - even one cycle helps. Perfect emergency calm-down.
- What is the Physiological Sigh pattern?
- inhale for 3 seconds, sip in for 1 seconds, exhale for 6 seconds — written as 3-1-6 — repeated 5 times.
- What is the most common mistake with Physiological Sigh?
- Making the second inhale as big as the first. It is a top-up on an already full lung, not a second breath.
- Is Physiological Sigh safe for everyone?
- There is no specific restriction recorded for this technique. Stop if you feel dizzy or short of breath. This is general information, not medical advice — check with a clinician if you are pregnant, managing a health condition, or unsure.
Used in these programs
Foundation Week · Workday Reset · Birth Prep
Also used for
Breathing Exercises for Pregnancy · Postpartum Breathing Exercises · Breathing Exercises for PCOS · Breathing Exercises for Menopause and Hot Flushes