Table 2.

Pre- and post-PST values of HRV parameters.

Situation	Parameter	Pre-test (mean ± SD)	Post-test (mean ± SD)	Paired t-test
				t-value	p-value	Cohen’s d
Relaxation	SDNN (ms)	69.14 ± 18.49	89.78 ± 25.46	−2.479	0.068	0.92
	RMSSD (ms)	46.6 ± 18.65	61.14 ± 18.8	−1.493	0.209	0.77
	LF power (ms2)	1673.2 ± 1,368	4,111 ± 3397.2	−2.316	0.081	0.94
	HF power (ms2)	1,219 ± 1282.8	1416.8 ± 804.3	−0.282	0.791	0.18
	LF/HF	2.298 ± 1.69	2.95 ± 1.432	−0.689	0.528	0.41
Crisis imagery	SDNN (ms)	57.62 ± 24.56	66.24 ± 13.45	−0.555	0.608	0.43
	RMSSD (ms)	38.66 ± 22.09	51.82 ± 9.28	−1.235	0.284	0.77
	LF power (ms2)	1,287 ± 960.7	748 ± 368.4	0.979	0.382	0.74
	HF power (ms2)	505.6 ± 477	871.4 ± 303.3	−1.678	0.168	0.91
	LF/HF	3.4 ± 2.3	1.014 ± 0.71	3.029	0.038*	1.4
Success imagery	SDNN (ms)	67.42 ± 31.64	83.38 ± 35.29	−0.622	0.567	0.47
	RMSSD (ms)	40.78 ± 21.83	62.2 ± 11.87	−1.597	0.185	1.21
	LF power (ms2)	1218.2 ± 1042.8	1640.4 ± 1689.9	−0.473	0.66	0.3
	HF power (ms2)	883.8 ± 990.9	1442.8 ± 632.4	−0.903	0.417	0.67
	LF/HF	1.933 ± 0.917	0.988 ± 0.572	2.843	0.046*	1.23

SDNN, standard deviation of the N-N; RMSSD, root mean square of Successive Differences; LF, low frequency; HF, high frequency.

^*p < 0.05.