TL;DR: Deep breathing, particularly around 6 breaths/min, increases parasympathetic nervous system activity, which can improve mood, blood pressure, mental health, sleep, and even dry eyes by increasing lacrimal gland stimulation.
Imagine it’s a hectic week, where you feel like you’re constantly running and trying to catch up from the moment you wake up, until maybe an hour or two before you finally get to sleep.
For some of you, you might not have to imagine this – you might be in the middle of it.
Stressful meetings, deadlines, a broken dishwasher… an endless barrage of stressors with no time to take a deep breath.
What is it about that deep breath? Why is that the go-to solution for hectic times, for anxiety, or any time you need to collect yourself and refocus?
Rest and Digest
It turns out that deep breathing has a direct neurophysiological connection with relaxation.
Deep, slow breathing activates your parasympathetic nervous system. This system helps you relax after experiencing stress, and also helps with more general, necessary-for-life “rest and digest” functions.
In practice, deep breaths tell your body you’re in a safe environment, and can afford to relax and unwind a bit.
In fact, there is evidence that deep, slow breathing is even more beneficial for older adults.
While breathwork like this can increase parasympathetic nervous system activation and reduce anxiety in anyone, these benefits appear to be particularly pronounced in people ~66 years old, as compared to people ~20 years old.
Resonance Frequency Breathing and HRV
You might be wondering how we could actually measure “parasympathetic nervous system activity.”
It’s a great question.
One increasingly common mechanism for measuring parasympathetic tone is with heart rate variability, or HRV.
Your heart is probably beating a little faster than once per second right now. Before I learned about HRV, I assumed that the “best” heart rate was one that was supremely rhythmic, something very even keel. Exactly every 0.8 second, my heart beats, a precise metronome at a grand symphony.
But it turns out, having some variability in between each heartbeat is a good thing.
HRV measures the variability (hence the name) in between each heartbeat. Rather than a steady “beat, beat, beat”, a higher (and healthier) HRV is something more akin to “beat… beat, beat.. beat” with a different amount of time in between each beat.
A higher HRV better equips you to respond to stressful situations. It’s an approximate indicator of parasympathetic activity, and a certain level is more adaptive for experiencing and responding adaptively to stressors.
I mention this because deep breathing is a very effective way to boost your HRV.
Specifically, a type of breathwork called “resonance frequency breathing” has been shown to increase parasympathetic tone.
Resonance frequency breathing is when your breathing rate and heart rate become synchronized. Typically this happens around 6 breaths per minute. Resonance frequency breathing can improve mood, lower blood pressure, and even lower anxiety.
Deep Breathing and Dry Eye
We have previously explored the link between dry eyes and depression, and how treating one may be key to treating the other. In a similar vein, resonance frequency breathing and similar HRV biofeedback techniques can be a useful supplement for treatment of depression.
All of these aspects fall under the purview of “digital strain”, a complex and interrelated network of symptoms.
At Umay, our focus is on addressing all of the interactions between dry eyes, sleep, depression & anxiety, and productivity. Boosts to one facet can reasonably be expected to have transitive benefits to another.
More directly, deep, abdominal breathing has also been shown to increase tear production. Specifically, trying to emulate that resonance frequency rhythm of ~6 breaths/min (4 s inhale, 6 s exhale) for 3 minutes increased tear meniscus volume.
The mechanism of this remarkable finding is thought to be due to the balance of parasympathetic activation. The lacrimal glands – as primary tear producers – are innervated predominantly by parasympathetic input.
The authors theorize that, similar to intense physical exercise, abdominal breathing decreases sympathetic activation, and the increase in parasympathetic activity stimulates the lacrimal glands to produce more tears.
REST combines gradual changes in temperature with subtle vibrational cues to help users have a heightened thermo-sensory experience (Thermal Meditation™), but also to guide their breathing to a resonance frequency.
We have built REST based on the remarkable science of how inter-related dry eye, breathing, sleep, and mental health are. Regular, daily usage can improve this suite of digital strain symptoms.
So the next time you’re in the middle of that hectic week, find a few minutes for yourself. A few minutes to breathe deeply, to disconnect: to REST.