The Effects of Ratio of Inhalation and Exhalation and Posture on Heart Rate Variability according to Sasang Constitution

Objectives We observed what effects both ratio of inhalation and exhalation(I/E) and posture have on heart rate variability(HRV) according to Sasang Constitution(SC).Methods HRV of 73 healthy participants who filled in self-questionnaires was recorded while they carried out 0.1Hz paced breathing(PB) with sitting, usual breathing(UB) with standing, and 0.1Hz PB with standing. PB was conducted to 4:6 or 6:4 of I/E and UB with sitting was executed before and after each breathing. Finally, HRV indices were analyzed of 60 participants(Soeum: 24, Soyang: 18, Taeeum: 18).Results & Conclusions In both self-questionnaires and HRV indices, there are not statistically significant between SC about the posture and I/E. SOEUM preferred 4:6 of I/E and showed lower mean RR and SDNN. SOYANG preferred 6:4 of I/E and showed higher mean RR and lower mean heart rate. TAEUM did not prefer I/E and showed the highest SDNN.