For a daily few-minute reset, or any stretch (working, winding down, recovering from a hard day) when you want to hold a calm, even baseline rather than fix an acute spike.
Coherent breathing slows you to roughly the 'resonance frequency' of the cardiovascular system (around six breaths per minute for most adults) where the natural rise and fall of heart rate with each breath (respiratory sinus arrhythmia) lines up in phase with the breath itself. At this tempo the heart-rate oscillations grow large and orderly, a marker of strong vagal (parasympathetic) activity, and the baroreflex that regulates blood pressure is most sensitive. The net effect is a nervous system tilted toward calm and a heart rhythm that looks more variable and adaptable, the 'coherent' state the name refers to.
Slow paced breathing around 5–6 breaths per minute is among the better-supported breathwork approaches, with studies reporting acute boosts in heart-rate variability and modest drops in self-reported stress, plus some signals on blood pressure and mood. Evidence quality is mixed (many trials are small, short, or use varied protocols) so treat coherent breathing as a well-founded daily regulation habit rather than a proven treatment. Everyone's ideal resonance frequency differs slightly, and benefits build with consistency.
The idea grew out of heart-rate-variability research: in the 1990s and 2000s Evgeny Vaschillo and Paul Lehrer identified a per-person 'resonance frequency' (typically ~4.5–6.5 breaths/min) and built HRV biofeedback around it. Stephen Elliott coined and popularised the term 'Coherent Breathing', settling on roughly five breaths per minute, while the HeartMath Institute promoted a related 'heart coherence' framing. The convergent ~5.5-breath/min target is now a staple of both clinical and consumer breath training.
Begin with a 5-minute session at whatever slow tempo feels sustainable (4-4 or 5-5 is fine) and lengthen toward 5.5 in / 5.5 out as it eases. Then grow the duration rather than the speed: work up to 10–20 minutes once or twice a day. Advanced practice means finding your personal resonance frequency and keeping the rhythm effortless for longer stretches.
Why 5.5 seconds specifically?
It sets a pace of about 5.5 breaths per minute, near the 'resonance frequency' where heart rate and breath sync most strongly for most adults. Anywhere in the 5–6 breath/min range works; the exact number isn't sacred.
How is this different from box breathing?
Box breathing uses equal counts with breath-holds and is often a quick pre-pressure reset. Coherent breathing has no holds and a specific slow tempo, and shines as a longer daily practice for baseline calm.
How long should a session be?
Even five minutes helps. For steadier day-to-day benefits, aim for 10–20 minutes most days, on its own or layered into another quiet activity.
Safety
Breathwork is a complement to (not a replacement for) professional medical care. If you have a heart, respiratory, or blood-pressure condition, are pregnant, or feel unwell, check with a clinician before practising breath-hold techniques.