Heart rate variability associated with walking Zen meditation Kinhin: Towards ?contemplatio actione?

To understand the effect of Zen experience on hemodynamic events elicited by deep walking Zen (Kinhin) meditation, we studied heart rate in experienced Zen meditator and beginner. The study took place over 4 sets of Kinhin meditations in a quiet, Zen practice hall. Each set of Kinhin lasted at least for 25 minutes. The first sets were used for habituation, and the data obtained from the following three sets were used for analysis. Power spectrum analysis showed distinctive change in frequency components. Very low frequency (VLF) components decreased and high frequency (HF) components increased for experienced meditator (p=0.05). Most notably, detrended fluctuations analysis (DFA) of HRV were around 1/2 for experienced and 0.85 for beginner. During Kinhin practice, we put our both hands on a lower chest so that we can keep our center of balance in the lower abdomen (Tanden) with lower abdominal muscle contraction, practice Tanden breathing, and keep mind free from distraction. We attribute the decrease of VLF components, increase of HF components and decrease of DFA exponent in experienced meditator to the parasympathetic stimulation, and to the minimal use of antigravity muscles in the optimal walking posture generated by Tanden located center of balance, as contrasted with the active use of antigravity muscles in the unstable posture by beginners.