Increased heart rate variability but no effect on blood pressure from 8 weeks of hatha yoga -- a pilot study

Twelve healthy women and men took part in an 8-week yoga program (60 min once a week). BP was measured with an automatic Omron mx3 oscillometric monitoring device and HRV with a Holter 24-hour ECG at baseline and 8 weeks after the intervention.There was no significant effect of inversion postures on BP. Nine out of 12 participants showed a significant increase in HRV (p < 0.05) at night (2 hours) on pNN50% (12.7 +/- 12.5 to 18.2 +/- 13.3). There were no significant changes in other HRV measures such as NN50, LF, HF, LF/HF ratio, LF normalized units (n.u.), HF n.u. and RMSSD.Eight weeks of hatha yoga improved HRV significantly which suggests an increased vagal tone and reduced sympathetic activity.