Table 2 Cross-sectional comparison in HRV time domain parameters for Tai Chi experts vs. naïve individuals.

From: Complexity-Based Measures of Heart Rate Dynamics in Older Adults Following Long- and Short-Term Tai Chi Training: Cross-sectional and Randomized Trial Studies

Outcome measures Tai Chi expert (n = 23) Tai Chi naïve (n = 52) Unadjusted p-valuea Adjusted p-valueb Adjusted p-valuec
HR (beats/min) 61.94 ± 10.04 61.17 ± 7.57 0.715 0.386 0.122
AVNN (ms) 991.48 ± 137.15 998.24 ± 124.09 0.835 0.419 0.178
SDNN (ms) 42.14 ± 12.93 45.03 ± 19.58 0.519 0383 0.142
RMSSD (ms) 23.91 ± 7.94 32.93 ± 23.21 0.074 0.061 0.163
pNN20 (%) 30.79 ± 14.52 36.80 ± 20.46 0.208 0.128 0.163
pNN50 (%) 5.05 ± 5.63 10.51 ± 16.07 0.118 0.075 0.209
  1. ap values calculated from unadjusted linear regression model.
  2. bp values calculated from linear model adjusting for age, BMI, and physical activity.
  3. cp values calculated from linear model adjusting for age, BMI, physical activity, and breathing intervals.
  4. Abbreviations: HR, heart rate; NN, normal-to-normal heartbeat intervals; AVNN, average NN intervals; SDNN, standard deviations of NN intervals; RMSSD, root mean square of the successive differences; pNN20 and pNN50, percentage of adjacent NN intervals that differ by greater than 20 and 50 milliseconds respectively.