| Time domain indexes | Group | Pre | Mid | Post |
| RMSSD (ms) | Utmost | 91.60 ± 52.84 | 122.80 ± 73.93 | 101.35 ± 45.63★★ |
| Moderate | 87.34 ± 60.70 | 134.93 ± 96.49. | 238.08 ± 180.54▲▲ | |
| High | 92.04 ± 58.06 | 90.09 ± 46.57 | 94.09 ± 45.89★★ | |
| PNN50 (%) | Utmost | 20.56 ± 8.76 | 25.54 ± 9.71 | 23.08 ± 7.84★★ |
| Moderate | 18.05 ± 13.04 | 26.05 ± 7.43▲ | 30.21 ± 7.94▲▲ | |
| High | 20.62 ± 11.66 | 22.25 ± 12.13 | 23.27 ± 8.25★ | |
| SDNN (ms) | Utmost | 77.25 ± 36.70 | 98.58 ± 48.95 | 86.20 ± 30.61★★ |
| Moderate | 74.73 ± 42.17 | 111.05 ± 67.25 | 150.69 ± 83.46▲▲ | |
| High | 77.02 ± 38.09 | 79.10 ± 37.62 | 75.01 ± 28.00★★ | |
| HR (beats/min) | Utmost | 71.25 ± 14.36 | 71.54 ± 15.65 | 63.55 ± 10.10▲ |
| Moderate | 75.23 ± 10.59 | 62.87 ± 9.65▲▲ | 58.30 ± 7.77▲▲ | |
| High | 70.68 ± 10.81 | 68.13 ± 8.32 | 62.89 ± 8.24▲ |