Repeatability value in heart rate associated with experienced Zen meditation

To understand the repeatability of hemodynamic events elicited by deep Zen meditation during Zazen, we studied heart rate in 5 experienced Zen meditators and beginners. The study took place over 8 sets of Zen meditations in a quiet, Zen practice hall. Each set of Zazen lasted at least for 25 minutes. The first sets were used for habituation, and the data obtained from the following seven sets were used for analysis. Power spectrum analysis showed distinctive change in frequency components. Very low frequency (VLF) components decreased for experienced meditators. Most notably, standard deviations from 7 sets of measurements within each subjects were significantly low for experienced meditators, showing increased repeatability. We attribute the decrease in VLF components to the less easily distracted meditation, and the increase in repeatability to the effective regulation of mind and body movement during experienced Zen meditation.