Table 1. Heart rate and heart rate variability variables (mean ± SD) of participants and statistical results.
| week 12 | week 16 | week 20 | week 25 | week 30 | week 35 | ANOVA | ||||
| HR (bpm) | p | ηp2 | ||||||||
| rest | 76.1±9.3 | 77.9±8.3 | 81.2±8.1 | 83.7±8.8 | 86.1±10.0 | 86.1±10.5 | week | F (5,175) = 22.7 | <.001 | .39 |
| post DB | 75.6±9.4 | 78.5±8.4 | 81.3±8.3 | 82.2±7.9 * | 85.0±10.0 | 84.7±9.9 | condition | F (1,35) = 5.9 | <.05 | .14 |
| week x condition | F (5,175) = 2.7 | <.05 | .07 | |||||||
| SDNN (ms) | ||||||||||
| rest | 47.6±20.2 | 42.1±16.8 | 42.1±17.9 | 39.9±13.4 | 36.7±19.5 | 36.8±19.2 | week | F (5,175) = 6.9 | <.001 | .16 |
| post DB | 50.6±20.4 | 47.9±20.5 | 45.5±19.4 | 39.1±13.8 | 40.5±20.5 | 40.0±15.9 | condition | F (1,35) = 22.4 | <.001 | .39 |
| week x condition | F (5,175) = 0.5 | = .80 | .01 | |||||||
| rMSSD (ms) | ||||||||||
| rest | 37.5±23.4 | 31.7±17.3 | 27.2±16.6 | 20.9±9.9 | 21.7±21.5 | 19.8±14.0 | week | F (5,175) = 10.0 | <.001 | .22 |
| post DB | 36.0±23.4 | 30.9±18.8 | 27.1±17.6 | 22.9±11.4 * | 22.3±22.4 | 22.0±14.6 | condition | F (1,35) = 0.7 | = .42 | .02 |
| week x condition | F (5,175) = 2.4 | <.05 | .06 | |||||||
| ln(LFRRI) (ms2) | ||||||||||
| rest | 6.0±1.1 | 5.9±0.9 | 6.0±0.9 | 5.6±0.7 | 5.6±0.9 | 5.5±0.9 | week | F (5,175) = 7.8 | <.001 | .18 |
| post DB | 6.3±1.0 | 6.2±0.9 | 6.1±0.9 | 5.8±0.7 | 5.8±0.9 | 5.7±0.9 | condition | F (1,35) = 17.3 | <.001 | .33 |
| week x condition | F (5,175) = 0.3 | = .90 | .01 | |||||||
| ln(HFRRI) (ms2) | ||||||||||
| rest | 5.8±1.3 | 5.6±1.1 | 5.3±1.0 | 5.0±0.9 | 4.7±1.2 | 4.7±1.1 | week | F (5,175) = 19.4 | <.001 | .36 |
| post DB | 5.8±1.1 | 5.5±1.1 | 5.3±0.9 | 5.0±1.0 | 4.8±1.2 | 4.9±1.1 | condition | F (1,35) = 0.3 | = .59 | .01 |
| week x condition | F (5,175) = 1.6 | = .16 | .04 | |||||||
| ln(LF/HF)RRI (-) | ||||||||||
| rest | 0.2±0.8 | 0.3±0.6 | 0.7±0.6 | 0.6±0.6 | 0.9±0.6 | 0.9±0.6 | week | F (5,175) = 11.5 | <.001 | .25 |
| post DB | 0.5±0.6 * | 0.7±0.5 * | 0.8±0.5 | 0.8±0.7 | 1.0±0.6 | 0.9±0.6 | condition | F (1,35) = 14.6 | <.01 | .29 |
| week x condition | F (5,175) = 2.5 | <.05 | .07 | |||||||
HR = heart rate; SDNN = standard deviation of normal-to-normal beat; rMSSD = root mean squared successive differences of R-R intervals; LF = low frequency (0.04–0.15 Hz); HF = low frequency (0.15–0.40 Hz); ln = natural logarithmic transformation; DB = deep breathing. *denotes a significant difference (p<.05) between rest and post DB in case of a significant univariate interaction effect.