Does a 5-minute Tai Chi Qigong exercise improve heart-rate variability in survivors of nasopharyngeal cancer?
A brief 5-minute Tai Chi Qigong exercise transiently improves heart-rate variability by increasing high-frequency power and decreasing low-frequency power in nasopharyngeal cancer survivors.
Purpose To explore the changes in heart-rate variability (HRV) of survivors of nasopharyngeal cancer (NPC) before, during, and after a Tai Chi (TC) Qigong exercise. Subjects and Methods Eleven survivors of NPC participated voluntarily in the study. The heart rate of each participant was measured continuously for 1 minute before the TC Qigong intervention, during the 5-minute TC Qigong intervention, and for 1 minute after the intervention, using a Polar heart-rate monitor. Spectral HRV was expressed in terms of normalised low frequency (LF) power, normalised high frequency (HF) power, and the low frequency/high frequency (LF/HF) power ratio. Results Both the LF-power and the HF-power components had significant time effects. However, the time effect of the LF/HF power ratio was not significant. Post hoc contrast analysis revealed a significant decrease in LF power and a concomitant increase in HF power during the 4th minute and 5th minute of the TC Qigong exercise. Conclusion Five minutes of TC Qigong exercise was found to improve HRV by increasing HF power and decreasing LF power, but these effects were transient. TC Qigong might be an appropriate exercise for improving the ANS function and psychological and cardiac health of survivors of NPC.
Fong et al. (Thu,) studied this question.