The mechanism
Heart rate is not regular: it rises on inhalation and falls on exhalation. This is respiratory sinus arrhythmia, normal and a sign of good health.
At around six breaths a minute, this oscillation resonates with the reflexes regulating blood pressure. Heart rate variability increases markedly. That state is what is called coherence.
What studies show
A measurable reduction in sympathetic activation during and shortly after the exercise, reduced felt anxiety, and a modest effect on blood pressure in people with hypertension.
What is not established: action on the immune system, on chronic disease, or a lasting effect beyond a few hours without repeated practice.
The common protocol
Three times a day, five minutes, six breaths a minute — about five seconds in, five seconds out. Seated, back straight, without forcing depth.
The point that matters: the exhalation must be at least as long as the inhalation. It carries the parasympathetic effect.
Unintentional hyperventilation is common at first: people breathe more deeply than needed and feel tingling or dizziness. Reduce the depth, not the slowness.
One reservation
In some anxious people, attending to the breath increases anxiety rather than reducing it. That is not a failure of the method: it indicates that a practice directed outward — walking, sound, making — will suit better.
our piece on rituals sets out how to fit a short practice into a ritual that holds.
This page is informational and does not replace medical advice.