Participant’s characteristics
| N | Minimum | Maximum | Average | Median | SD | |
| Age (in years) | 28 | 26 | 67 | 49.14 | 49.0 | 9.93 |
| BMI (in kg/m²) | 28 | 20.07 | 30.04 | 23.97 | 23.48 | 2.12 |
| Run time (in hour:min:s) | 23 | 15:25:14 | 28:57:45 | 23:09:37 | 23:30:12 | 03:57:03 |
| HR in U1 | 28 | 50 bpm | 109 bpm | 72.07bpm | 71bpm | 11.76 bpm |
| HR in U2 | 24 | 62 bpm | 127 bpm | 85.75 bpm | 80 bpm | 15.95 bpm |
| HR in U3 | 27 | 55 bpm | 96 bpm | 69.48 bpm | 69 bpm | 8.47 bpm |
| SDNN U1 | 26 | 35.88 ms | 208.74 ms | 74.81 ms | 60.495 ms | 38.38 ms |
| SDNN U2 | 21 | 23.89 ms | 416.40 ms | 81.49 ms | 45.35 ms | 96.68 ms |
| SDNN U3 | 25 | 34.88 ms | 147.8 ms | 66.88 ms | 59.79 ms | 23.64 ms |
| RMSSD U1 | 27 | 26.8 ms | 353.7 ms | 73.17 ms | 40.9 ms | 76.65 ms |
| RMSSD U2 | 22 | 24.8 ms | 423.5 ms | 126.73 ms | 96.05 ms | 107.93 ms |
| RMSSD U3 | 26 | 25.1 ms | 177.4 ms | 54.88 ms | 45.9 ms | 31.97 ms |
| pNN50 U1 | 27 | 1.9% | 49.7% | 14.80% | 7.1% | 14.30% |
| pNN50 U2 | 22 | 0.7% | 55.6% | 17.53% | 11.7% | 17.71% |
| pNN50 U3 | 26 | 2.6% | 25.9% | 10.81% | 9.4% | 7.26% |
| VQ U1 | 26 | 0.23 | 1.78 | 0.86 | 0.855 | 0.41 |
| VQ U2 | 21 | −1.65 | 1.78 | 0.65 | 0.66 | 0.81 |
| VQ U3 | 25 | 0.38 | 1.38 | 0.87 | 0.85 | 0.34 |
BMI, body mass index; bpm, beats per minute; HR, heart rate; N, number of participants with complete data sets; pNN50, the percentage of pairs of RR intervals that are more than 50 ms apart; RMSSD, root mean square of successive differences; SDNN, the SD of all normal RR intervals; U1, investigation 7 days before the run; U2, investigation immediately after the run; U3, investigation 7 days after the run; VQ, vegetative quotient.