Box breathing (4-4-4-4)
Slow paced breathing at ~6 breaths/min raises vagal tone and shifts the autonomic balance.
Why
Slow paced breathing at ~6 breaths/min raises vagal tone and shifts the autonomic balance. Free, instant, no contraindications.
The technique
- 1
Inhale slowly through the nose for 4 seconds.
- 2
Hold the breath in, relaxed, for 4 seconds.
- 3
Exhale slowly through the nose or pursed lips for 4 seconds.
- 4
Hold the breath out, relaxed, for 4 seconds, then repeat.
Evidence
Laborde 2022 Neurosci Biobehav Rev meta-analysis (223 studies): paced breathing at ~6 breaths/min, the rhythm box-breathing produces, reliably increases vagally-mediated HRV both during and immediately after practice. Free, instant, no known contraindications; effect size acute and modest, cumulative effects emerge with regular practice.