Inward-attention meditation increases parasympathetic activity: a study based on heart rate variability.
Biomedical research (Tokyo, Japan) October 1, 2008 Shr-Da Wu, Pei-Chen Lo
Inward-attention meditation, a technique practiced in Zen that focuses attention inward rather than on slow breathing, shifts the autonomic nervous system toward greater parasympathetic activity. Experienced meditators showed a decrease in the LF/HF ratio and LF norm and an increase in HF norm compared to non-meditators during rest, indicating improved sympathovagal balance. Regular oscillating rhythms of heart rate appeared in the high-frequency band of heart rate variability when the LF/HF ratio was small, a pattern previously observed only in the low-frequency band during slow breathing. These oscillations had smaller amplitude in the high-frequency band.