Table 1.

Multilevel regression predicting logarithmized root mean square of successive differences (lnRMSSD) before, during, and after the slow-paced breathing intervention (N=60).

Predictors	lnRMSSD
	Estimate, b (95% CI)	P value
Intercept	3.53 (3.44 to 3.62)	<.001
Metabolic equivalents	–0.35 (–0.36 to –0.35)	<.001
Smoking (no vs yes)	–0.03 (–0.06 to –0.00)	.03
Trigger (0=random vs 1=AddHRVra)	–0.35 –0.38 to –0.32	<.001
Time (before intervention vs during intervention [breathing])	0.17 (0.16 to 0.19)	<.001
Time (before intervention vs after intervention)	0.03 (0.02 to 0.04)	<.001
Trigger×time (before intervention vs during intervention [breathing])	0.08 (0.02 to 0.14)	.02
Trigger×time (before intervention vs after intervention)	0.12 (0.07 to 0.16)	<.001

^aAddHRVr: additional heart rate variability reductions.