Table 3.
Heart rate and heart rate variability (HRV) parameters (in absolute and relative units) in supine (SU) and standing (ST) positions, 1 day before (Pre) and 1 day after (Post) live high – train low (LHTL) intervention.
| XC | NC | ||||||
|---|---|---|---|---|---|---|---|
| Pre | Post | p | Pre | Post | p | ||
| HRSU | bpm | 51.6 ± 5.7 | 54.9 ± 6.0 | 0.05 | 46.8 ± 14.6 | 46.0 ± 20.8 | 0.13 |
| % | – | 6.9 ± 10.4 | 0.04 | – | 6.0 ± 10.9 | 0.17 | |
| HRST | bpm | 77.2 ± 9.7 | 81.6 ± 8.8 | 0.23 | 73.1 ± 21.5 | 72.4 ± 32.4 | 0.04 |
| % | – | 6.2 ± 12.5 | 0.09 | – | 9.9 ± 11.6 | 0.05 | |
| LFSU | ms2 | 2726 ± 2906 | 4294 ± 3485 | 0.17 | 3493 ± 2408 | 4479 ± 4164 | 0.89 |
| % | – | 188.0 ± 264.8 | 0.03 | – | 70.0 ± 201.6 | 0.36 | |
| LFST | ms2 | 5602 ± 3773 | 6585 ± 4174 | 0.41 | 6555 ± 4368 | 5932 ± 5027 | 0.79 |
| % | – | 52.7 ± 126.8 | 0.18 | – | -2.3 ± 71.0 | 0.93 | |
| HFSU | ms2 | 4981 ± 3818 | 5151 ± 3299 | 0.77 | 6212 ± 4030 | 3562 ± 2638 | 0.17# |
| % | – | 30.6 ± 85.8 | 0.24 | – | -8.3 ± 129.7 | 0.86# | |
| HFST | ms2 | 1393 ± 2340 | 1244 ± 1703 | 0.64 | 819 ± 651 | 677 ± 515 | 0.25 |
| % | – | 65.0 ± 171.6 | 0.22 | – | -15.0 ± 36.0 | 0.28 | |
| LF + HFSU | ms2 | 7707 ± 5905 | 9444 ± 5616 | 0.09 | 9642 ± 5535 | 7951 ± 6241 | 0.43 |
| % | – | 61.4 ± 101.4 | 0.06 | – | 16.8 ± 149.6 | 0.76 | |
| LF + HFST | ms2 | 6995 ± 5627 | 7829 ± 5490 | 0.51 | 7333 ± 4615 | 6580 ± 5303 | 0.77 |
| % | – | 47.5 ± 126.6 | 0.22 | – | -3.4 ± 67.7 | 0.89 | |
| LFSUnu | n.u. | 31.9 ± 17.3 | 44.8 ± 19.7 | 0.08 | 40.2 ± 14.9 | 47.1 ± 21.1 | 0.44 |
| % | – | 68.1 ± 115.4 | 0.06 | – | 23.3 ± 58.5 | 0.29 | |
| LFSTnu | n.u. | 83.4 ± 12.2 | 86.6 ± 6.0 | 0.34 | 84.6 ± 23.0 | 77.5 ± 32.7 | 0.95 |
| % | – | 5.4 ± 14.8 | 0.23 | – | -0.1 ± 2.7 | 0.95 | |
| HFSUnu | n.u. | 68.1 ± 17.3 | 55.2 ± 19.7 | 0.08 | 54.3 ± 17.5 | 40.6 ± 18.9 | 0.44 |
| % | – | -13.9 ± 35.5 | 0.20 | – | -5.5 ± 39.2 | 0.70 | |
| HFSTnu | n.u. | 16.6 ± 12.2 | 13.3 ± 8.0 | 0.34 | 9.1 ± 3.3 | 8.4 ± 4.1 | 0.96 |
| % | – | 17.5 ± 111.9 | 0.59 | – | -0.1 ± 32.0 | 0.99 | |
| RMSSDSU | ms | 108 ± 45 | 114 ± 34 | 0.49 | 115 ± 48 | 95 ± 51 | 0.31 |
| % | – | 13.9 ± 38.2 | 0.23 | – | -9.2 ± 42.5 | 0.56 | |
| RMSSDST | ms | 51 ± 25 | 42 ± 26 | 0.14 | 43 ± 15 | 34 ± 16 | 0.06 |
| % | – | -11.0 ± 38.3 | 0.34 | – | -17.3 ± 22.4 | 0.06 | |
With heart rate (HR), low (LF) and high (HF) frequency spectral power, LF and HF in normalized units (LFnu, HFnu), and square root of the mean of the sum of the squares of differences between adjacent normal R-R interval (RMSSD). XC for cross-country skiers, and NC for Nordic-combined groups. Data are reported as mean and standard deviation (SD). With p < 0.05 for significant difference between Pre and Post and # (p < 0.05), in italic, for difference of change Pre vs. Post between XC and NC.