Your body already does this. Twice an hour or so, and reliably after crying, you take a double inhale followed by a long exhale. It reinflates collapsed alveoli and offloads carbon dioxide. Done deliberately, it is among the fastest ways to lower physiological arousal that does not involve a medicine.
How
- Inhale through the nose until the lungs feel comfortably full.
- Take a second, shorter sip of air on top of that.
- Let it out slowly through the mouth, longer than the inhale, until empty.
- Repeat two or three times.
Why the long exhale matters
Heart rate rises slightly on inhalation and falls on exhalation — respiratory sinus arrhythmia. Making the exhale longer than the inhale shifts the balance toward parasympathetic activity. This is the mechanism nearly all slow-breathing practices share; the double inhale simply makes it more efficient.
It is free, it is portable, and nobody can tell you are doing it.
A caveat
Breathing techniques are useful for acute stress. They are not a treatment for an anxiety disorder, and if worry is affecting your sleep, work or relationships, that deserves proper attention rather than a breathing exercise. We can point you toward local mental health services, most of which accept self-referrals.