Sighing is a natural phenomenon within breathing. We sigh roughly every 5 minutes, and we naturally sigh throughout the night when we sleep. Like anything that occurs naturally in the body, sighing has a purpose.
On the inhale:
Think of your alveoli (air sacks) in the lungs as little balloons. They expand as we breathe in, and collapse as we breathe out. When we breathe in moist air (as we do through the nose) sometimes the sides of the ‘balloon’ stick together and the alveoli stay collapsed. A sigh, which typically involves a bigger than average inhale, is a way of increasing pressure within the alveoli and forcing them back open. A sigh can therefore be thought of as a small reset button that keeps the lungs working properly.
On the exhale:
A typical sigh involves a long slow exhale through the mouth. A slow exhale activates the parasympathetic nervous system (rest & digest) and the offloading of stale air through the mouth acts as a natural stress reliever.
Sighs & emotion
Sighs are highly correlated with emotion – both negative and positive – and naturally induce feelings of relief. We will sigh when we are agitated or stressed, as a way of offloading stress. We will also sigh when we are contented as a way of indicating relief and contentment. You may notice that people will frequently sigh at end of a period of sobbing, and also when they have held their breath in response to a threat and the threat passes. Sighing can therefore also be thought of as a reset button for our emotions.
How to use a sigh
Once we understand the purpose and mechanism of the sigh, we can use it consciously to our advantage. We can choose to sigh to gain relief from stress in the moment, or to regulate our emotions. We can also use it to regulate our breathing patterns as, if we notice our breathing pattern is choppy, erratic, or restricted, a sigh will often reset it.
The physiological sigh
First noted in around the 1930’s and now spoken about extensively by neuroscientist Andrew Huberman, the physiological sigh is a specific type of sigh that is proven as a potent stress reliever. Again, it seems to occur naturally during sleep, and during times of stress such as claustrophobia. It is also seen extensively in animals. The physiological sigh uses the phrenic nerve (rather than the vagus nerve) which means it is fast acting and provides immediate relief.
To undertake a physiological sigh simply take a two part inhale in through the nose i.e. inhale half lung capacity, pause, inhale second half, then slowly exhale through the mouth. The two part inhale maximally expands the lungs and increases energy and focus, the slow exhale soothes and calms.
Use a quick physiological sigh to take the edge off an immediate stressor i.e. taking a penalty kick, walking into an interview. Or try 5-10 rounds to reset your breathing and shift your emotional state.
Double it up
We can amplify the calming effect of a physiological sigh by adjusting our gaze.
Eye position and gaze are intrinsically linked to the stress response, because vision and focus are critical in keeping us safe from threat. Focusing on things close up and with intense focus i.e. paper work or a mobile phone tends to activate the sympathetic nervous system (fight or flight), whilst looking into the distance with a soft gaze tends to activate the parasympathetic nervous system (rest & digest). This makes logical sense if you consider that you are descended from animals living in the wild; when safe and at ease an animals eyes will calmly survey the surroundings with a soft gaze and soft focus, when a threat is detected the eyes will shift to a laser like focus on the threat. Our innate physiology has really not changed that much.
It is possible to amplify the calming effect of a sigh by adopting a panoramic gaze and looking at the furthest away point, whilst taking your few deep sighs. Ideally this would be the horizon, but if that is not possible then the furthest away point in the room will do.
Soften your gaze and sigh it out. Notice how you feel.