Table 3.

Correlation coefficients between frequency-domain and time-domain HRV measures

	RMS		rMSSD
	r	P value	r	P value
sqrtLF	0.91	<0.0001	0.78	<0.0001
sqrtHF	0.86	<0.0001	0.95	<0.0001
sqrtTOTAL	0.96	<0.0001	0.83	<0.0001