Characteristics of the cosine curve
| Parameters | Mesor | Amplitude | Acrophase (mean (SD)) |
| SDNN | 50.0 Age0.27 | 21.1 Age−0.09 (p > 0.05) | 03:51 (01:33) |
| SDNNi | 38.1 Age0.27 | 7.2 Age0.44 | 04:00 (01:22) |
| rMSSD | 26.8 Age0.27 | 7.3 Age0.55 | 02:45 (01:20) |
| pNN50 | 3.8 Age0.27 | 2.4 Age0.87 | 02:28 (01:16) |
| VLF | 25.8 Age0.31 | 5.9 Age0.34 | 04:44 (01:13) |
| LF | 20.8 Age0.27 | 4.0 Age0.32 | 03:37 (01:43) |
| HF | 15.4 Age0.27 | 3.9 Age0.62 | 03:06 (01:09) |
| LF:HF | 0.01 Age2–0.18 Age+1.79 | 0.16 Age0.32 | 14:27 (00:49) |
| mean RR | 502.5 Age0.16 | 63.3 Age0.75 | 02:54 (00:54) |
Time domain indices and LF:HF in absolute values; LF, HF, and mean RR in msec, age in years.