Meditation, especially slow breathing, is known to influence the heart rate variability (HRV). Researchers in Taiwan studied the effects of inward attention during meditation on HRV (Wu and Lo, 2008). Inward attention is a critical process for achieving the state of transcendental consciousness in Zen-meditation.
Ten practitioners of Zen-meditation, and 10 people with no meditation training experience as controls were involved in the study (Wu and Lo, 2008). The study found that inward attention during meditation led to the reduction of low/high frequency (LF/HF) ratio, and the improvement of a sympatho-vagal balance for parasympathetic activities.
In addition, there was a regular oscillating rhythms of the heart rate, which commonly occurs during slow breathing (Wu and Lo, 2008). The study indicates that inward-attention meditation may promote parasympathetic activities and regular oscillations of the heart rate. Further studies may help understand more potential influences on physical and mental activities as well as the mechanisms of such effects.
Wu, S. D. and Lo, P. C. (2008) Inward-attention meditation increases parasympathetic activity: a study based on heart rate variability. Biomed Res 29, 245-250.