Comparison of acute heart rate variability responses to relaxation alone vs. relaxation preceded by Hatha yoga

The objective of this study was to compare the acute heart rate variability responses to relaxation alone versus relaxation preceded by Hatha yoga. Twenty women and men (aged 18-50 years) participated in the study. Participants completed a yoga plus relaxation (YR) session and a relaxation only (R) session. The YR condition showed significant changes from baseline in HR (bpm, p < 0.001), RR (ms, p < 0.001), pNN50 (%, p = 0.009), LF (% p = 0.008) and HF (% p = 0.035). The R condition showed significant changes from baseline in HR (bpm, p < 0.001), RR (ms, p < 0.001), HF (ms2, p = 0.004), LF (%, p = 0.005), HF (%, p = 0.008) and LF/HF (%, p = 0.008). There were no significant differences between conditions for the changes from baseline for any of the variables. The results demonstrate that relaxation produces favorable changes in indices of heart rate variability whether alone or preceded by about of Hatha yoga.