Box breathing (also known as square breathing) is a regulated autonomic technique used by clinical psychologists and Navy SEALs to instantly down-regulate the sympathetic nervous system and stimulate the vagus nerve.
The 4-Step Box Breathing Protocol
- Inhale (4 Seconds): Inhale slowly through your nose, expanding your diaphragm.
- Hold (4 Seconds): Retain the breath gently without straining your throat.
- Exhale (4 Seconds): Release air smoothly through your mouth or nose.
- Hold (4 Seconds): Pause with empty lungs for 4 seconds before the next cycle.
Repeat for 4 to 6 cycles (approx. 3 minutes) to restore baseline heart rate variability (HRV).
Peer-Reviewed Clinical Sources & Research
- PubMed (NIH/NLM). Brief Structured Respiration Practices Enhance Mood and Reduce Physiological Arousal. Cell Reports Medicine, PMID: 36630953.
- Mayo Clinic. Breathing techniques to calm your mind and lower blood pressure. Mayo Clinic Health Information.