TABLE 2.

HR and HRV data for the whole sleep period.

					Comparisons
	Lower SJL		Higher SJL		Lower SJL	Higher SJL
	Workday	Free day	Workday	Free day	p	p
HR (1/min)	59.1 (2.1)	58.1 (1.3)	57.8 (1.8)	57.2 (2.1)	0.520	0.739
SDNN	86.8 (7.3)	95.1 (6.4)	91.5 (6.2)	102.2 (6.9)	0.088	0.018
RMSSD	61.1 (8.3)	64.9 (7.4)	64.1 (4.5)	72.8 (5.4)	0.422	0.092
pNN50	32.8 (5.1)	35.2 (4.3)	37.7 (3.6)	44.2 (3.9)	0.540	0.107

Mean HR and HRV data were averaged for the time period from sleep onset to waking up. Data for the workday and the free day were compared within both groups of participants. Mean (SEM), paired t-test, n = 17 and 14 for the group with lower and higher SJL, respectively.