A new study on controlled breathing has found the best way to calm our bodies, and even boost our mood.
The research examined 100 people over the course of several weeks.
It compared four different types of breathing: mindfulness, cyclic sighing, box breathing and hyperventilation.
Professor Luke O'Neill told The Pat Kenny Show what this all means.
"Mindfulness is you're just aware of your breathing, you don't intervene," he said.
"Box breathing is you breathe in - say - for three seconds, hold for three seconds [and] breathe out for three seconds.
"The most strange one is hyperventilation - it's called hyperventilation with retention.
"You take in a deep breath, you hold it, let it out quickly and then another long breath.
"So kind of long-short breathing."
The winning method
Prof O'Neill said the cyclic method had the most benefits.
"The cyclic did the best, really. What I mean by best is their mood improved," he said.
"They reported a mood change, their heart rate improved and then - very importantly - physiological in their body things seemed to improve as well.
"You take in a short breath and let out for longer... you take a tiny breath and a longer breath in - a kind of double gasp - and then a long out.
"The trick is: short in, longer out - keep doing that for five minutes, it doesn't work if you do it for 10 seconds."
Retaining CO₂
Prof O'Neill said there seems to be a cumulative effect, which led to people "feeling better and better" across several days.
"The thing for me as a scientist is: what's the mechanistic chemical basis for this?" he said.
"You breathe in oxygen, you breathe out CO₂ - and if you kind of retain a bit, CO₂ builds up in your body for longer.
"That seems to have beneficial effects, it seems to calm down various parts of your body.
"They're recommending we should all be doing cyclic sighing: it's cheap, it doesn't cost you any money".
He said there could also be a connection to the vagus nerve, which has a calming effect when it is triggered.
"They reckon this breathing is somehow connected to the vagus nerve, which now fires in a more calm way.
"The thing to get going is your vagus nerve," he added.
Listen back to the full segment below (and breathe):
