Influence of qigong self-control method on heart rate variability

Telecardiogram and spectral analysis were used to study the influence of qigong self-control method on heart rate variability in 23 subjects. When practicing qigong for more than 20 minutes, the low-frequency (II) (0.05-0.15 Hz) and the high-frequency (0.15-0.55 Hz) components of the power spectra density of R-R interval variability were significantly greater. During practicing qigong, mean R-R interval and R-R variance tend to decrease, but the low-frequency (II) and high-frequency components of the power spectra density tend to increase. According to the change of low-frequency (II):high-frequency ratio, the course of practicing qigong can be divided into two phases. In the 5 minutes after practicing qigong, the low-frequency (II):high-frequency ratio was increase with increased sympathetic activity. At the end of the practicing, the low-frequency (II):high-frequency ratio significantly decreased with increased parasympathetic activity.