Biofeedback for Respiratory Sinus Arrhythmia and Tanden Breathing among Zen Monks: Studies in Cardiovascular Resonance

Abstract

Resting heart rate is characterized by several overlapping oscillations at several frequencies. Oscillations at each frequency is related to a specific set of reflexes that plays a role in cardiovascular homeostasis. Recent research on biofeedback training to increase the amplitudes of these frequencies has found that people can accomplish this task by breathing at frequencies that resonate with oscillations at slower frequency ranges. The slower heart rate oscillations appear to reflect baroreflex activity. Such biofeedback training may exercise the baroreflexes and thereby increase baroreflex efficiency and decrease vulnerability to disorders characterized by autonomic hyperreactivity (e.g., asthma, hypertension, anxiety disorders). Zen monks have a low rate of cardiovascular disease, and also breathe very slowly during the practice of Zazen, causing resonance with oscillations in cardiovascular variables related to heart rate and blood pressure control. One very experienced monk breathed at a rate of approximately once/minute, and appeared to stimulate reflexes that control vascular tone and body temperature.