Table 3. HRV measures at baseline, intervention, and during post-session. Values are grouped as mean±SD, mean difference, and percentage change (%).
Pairwise comparison between states: S1 vs. S2, S1 vs. S3, S2 vs. S3. * indicates the significance level at p < 0.05 (between S1 and S2); $$ and $$$ indicate the significance level at 0.01 and 0.001, respectively (between S2 and S3); and # indicates the significance level at 0.05 between the MSRT and SR sessions.
Variable and initials used: Mean RR: mean RR interval (ms); SDNN: standard deviation of normal to normal RR intervals (ms); RMSSD: root mean square standard deviation, pNN50: LF/HF ratio, nu-normalized units; LF: low frequency, HF: high frequency, nu: normalized units. S1: baseline, S2: during intervention, S3: post.
| Mean±SD | Mean difference | % change | ||||||||||
| Variable | Baseline (S1) | Intervention (S2) | Post (S3) | S1-S2 (BS-Int) | S1-S3 (BS-Post) | S2-S3 (Int-Post) | S1-S2 (BS-Int) | S1-S3 (BS-Post) | S2-S3 (Int-Post) | |||
| Time domain | Mean RR | MSRT | 764±88.3 | 756±109.66 | 755±92.12 | -7.96 | -8.41 | -0.45 | -1.04 | -1.10 | -0.06 | |
| SR | 757±76.97 | 761±71.45 | 729±91.09 | 3.80 | -27.98 | -31.78 | 0.50 | -3.69 | -4.18 | |||
| SDNN | MSRT | 127±130.35 | 127±75.51# | 107±71.42 | -0.14 | -19.72 | -19.58 | -0.11 | -15.55 | -15.46 | ||
| SR | 86±59.77 | 83±40.00 | 98±63.08 | -3.37 | 12.01 | 15.38 | -3.91 | 13.90 | 18.53 | |||
| RMSSD | MSRT | 154±188.51 | 141±113.87 | 127±105.28 | -12.30 | -26.78 | -14.48 | -8.01 | -17.44 | -10.25 | ||
| SR | 90±86.35 | 85±60.84 | 100±89.37 | -4.25 | 11.08 | 15.34 | -4.75 | 12.36 | 17.96 | |||
| pNN50 | MSRT | 36±28.69 | 33±25.50 | 32±26.03 | -2.76 | -4.26 | -1.49 | -7.72 | -11.90 | -4.53 | ||
| SR | 28±22.86 | 26±19.01 | 28±24.84 | -2.06 | 0.31 | 2.37 | -7.30 | 1.08 | 9.05 | |||
| Frequency domain | LF/HF | MSRT | 1.40±1.76 | 2.67±2.78 | 1.15±1.07$$$ | 1.27 | -0.25 | -1.52 | 90.63 | -17.89 | -56.93 | |
| SR | 1.61±1.49 | 1.46±0.98 | 1.75±1.28 | -0.15 | 0.14 | 0.29 | -9.50 | 8.61 | 20.01 | |||
| LFnu | MSRT | 48.42±16.38 | 57.45±17.62* | 45.99±17.19$$ | 9.03 | -2.43 | -11.46 | 18.65 | -5.02 | -19.95 | ||
| SR | 53.31±17.88 | 51.98±14.34 | 56.63±17.19 | -1.33 | 3.32 | 4.65 | -2.50 | 6.23 | 8.95 | |||
| HFnu | MSRT | 51.29±16.33 | 42.31±17.45* | 53.68±17.06$$ | -8.98 | 2.39 | 11.37 | -17.51 | 4.66 | 26.87 | ||
| SR | 46.39±17.69 | 47.78±14.31 | 43.12±17.03 | 1.38 | -3.28 | -4.66 | 2.98 | -7.06 | -9.75 | |||