Table 3.

Descriptive statistics of nonlinear HRV features during holidays and during university examination

Meas.	Rest session					Stress session
	Mean	SD	Med.	25th	75th	Mean	SD	Med.	25th	75th
SD1	0.024	0.01	0.023	0.016	0.03	0.024	0.011	0.024	0.012	0.033
SD2	0.078	0.024	0.079	0.061	0.094	0.048	0.022	0.046	0.031	0.057
D2	2.828	1.09	3.179	2.244	3.544	1.649	1.282	1.494	0.468	2.574
En(0.2)	1.095	0.125	1.102	1.02	1.192	0.99	0.24	0.932	0.841	1.177
En(rmax)	1.122	0.101	1.113	1.057	1.217	1.086	0.171	1.017	0.952	1.217
En(rchon)	1.112	0.111	1.106	1.052	1.217	0.983	0.243	0.951	0.842	1.177
α1	1.413	0.16	1.438	1.283	1.51	1.054	0.446	1.043	0.69	1.447
α2	0.781	0.182	0.715	0.644	0.953	0.759	0.135	0.766	0.678	0.851
lmax	286.7	111.2	282	178	384	213.4	136.5	179	86	282
lmean	11.09	2.478	10.43	9.518	12.68	14.88	6.771	13.32	11.10	16.92
REC	33.46	6.27	32.57	29.55	37.59	42.24	12.05	43.25	36.11	49.02
DET	98.61	0.86	98.78	98.31	99.19	98.75	1.28	99.25	98.14	99.63
ShEn	3.171	0.233	3.139	3.043	3.362	3.421	0.397	3.417	3.21	3.642