An example of RR interval time series (500 intervals) measured during supine rest and during low intensity exercise.

<p>An example of RR interval time series (500 intervals) measured during supine rest and during low intensity exercise.</p

Mean (95% confidence interval) for selected HRV indices at rest before (pre), and after 21 weeks of training (post) in the endurance, strength, combined strength and endurance training, and control group.

<p>HR, heart rate; SDNN, standard deviation of NN intervals; HFP, high frequency power; LFP low frequency power; LFP/HFP, ratio between LFP and HFP; CI_1–5, complexity index of multiscale entropy analysis over the scales of 1 to 5. Statistically significant changes were not observed.</p

Individual and the mean changes in the HR complexity index.

<p>The index for the scales 1 to 2 (CI_1–2) was measured during steady state exercise at baseline (pre) and after 21 weeks in the endurance training (E), combined strength and endurance training (SE), strength training (S) and the control (C) group. **significant change (P<0.01) compared to the baseline.</p

Heart rate and heart rate dynamics during steady state exercise.

<p>Heart rate (HR, A), standard deviation of NN intervals (SDNN, B), high frequency power (HFP, C) and HR complexity index for the scales 1 to 2 (CI_1–2, D) measured at baseline (0) and after 10 and 21 weeks of endurance (E), strength (S) or combined strength and endurance training (SE) and in the control group (C). *significant change (P<0.05) compared to the baseline, **P<0.01, ***P<0.001.</p

Complexity-based and Traditional measures of sway for the Randomized to Tai-Chi and Randomized to usual care groups across visits.

a<p>values provided are mean ± standard deviation. ^bvalues are estimated slope (lower 95% confidence interval, upper 95% confidence interval). ^cp-values for testing for an effect of age indicated by p-age. ^dp-values for comparing mean rates of change among Tai-Chi vs. usual care groups indicated by p-group*time.</p><p>Complexity-based and Traditional measures of sway for the Randomized to Tai-Chi and Randomized to usual care groups across visits.</p

Associations between changes in both complexity-based (A, B) and traditional measures (C, D) of sway vs. Tai Chi dosage (total hours practiced) among Tai Chi naïve individuals exposed to six months of training.

<p>Percent changes in sway were assessed between the baseline and 6 month follow up visit for the anterioposterior (AP) and mediolateral (ML) planes and during eyes-open (EO) and eyes-closed (EC) conditions. Analyses excluding the largest x-axis value (i.e. potential outlier) reduced ΔAP EC p-value to a non-significant level (p = 0.423), however, the p-value for the ΔML EC was less affected (p = 0.037).</p

Details of the intrinsic mode functions (IMFs) and MSE scales used for the long-term Tai-Chi comparison between Naïve and Expert groups.

<p>The last three columns show the statistical comparison between the Young and Naive at baseline which led to the selection of these IMFs.</p>a<p>values provided are mean ± standard deviation with units of complexity index divided by MSE scale range, C_I/R(τ).</p><p>Details of the intrinsic mode functions (IMFs) and MSE scales used for the long-term Tai-Chi comparison between Naïve and Expert groups.</p

Associations between changes in physical function and Tai Chi dosage (total hours practiced) among Tai Chi naïve individuals exposed to six months of training.

<p>Percent changes in function were assessed between the baseline and 6 month follow-up visit for single leg stance time (SLST) and timed up and go (TUG) parameters. Analyses excluding the largest x-axis value (i.e. potential outlier) reduced ΔSLST to a non-significant level (p = 0.286), however, the p-value for the ΔTUG was less affected (p = 0.0062).</p

Schematic illustration of the course-graining procedure for multiscale entropy.

<p>x_i represents the original time-series samples. y_j represents the coarse-grained samples at the indicated scale. Adapted from Costa et al. 2002 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114731#pone.0114731-Costa4" target="_blank">[72]</a>.</p

Participant characteristics for observational and randomized groups.

a<p>values provided are mean ± standard deviation.</p>b<p>Physical Activity Level descriptions:</p><p>4 = Run about 1 mile per week OR walk about 1.3 miles per week OR spend about 30 minutes per week in comparable physical activity.</p><p>5 = Run about 1 to 5 miles per week OR walk 1.3 to 6 miles per week OR spend 30 to 60 minutes per week in comparable physical activity.</p><p>6 = Run about 6 to 10 miles per week OR walk 7 to 13 miles per week OR spend 1 to 3 hours per week in comparable physical activity.</p><p>Participant characteristics for observational and randomized groups.</p