TY - JOUR
T1 - Face immersion increases vagal activity as assessed by heart rate variability
AU - Hayashi, Naoyuki
AU - Ishihara, Mutsuhisa
AU - Tanaka, Ayumu
AU - Osumi, Tomonori
AU - Yoshida, Takayoshi
N1 - Funding Information:
Acknowledgement This work was supported by a grant-in-aid from the Ministry of Education, Science and Culture of Japan under grant number 8780072 to NH.
PY - 1997/11
Y1 - 1997/11
N2 - We examined whether the diving reflex without breath-holding (face immersion alone) increases vagal activity, as determined by heart rate variability. A group of 15 men [mean age 20 (SD 3) years, height 172 (SD 5) cm, body mass 68 (SD 9) kg] performed 12 trials at various breathing frequencies (5, 10, 15, 20, 30 breaths·min-1 and uncontrolled breath) with or without face immersion. The R-R intervals of the ECG and gas exchange variables were recorded during the 2 min of each trial. The subjects immersed their faces in 8-10°C water while breathing through a short snorkel. The subject sat in the same position either with or without face immersion. The mean R-R interval (RR(mean)), standard deviations (SD(RR)) and coefficient of variance (CV(RR)) of the R-R interval were calculated from the R-R intervals during 30-130 s. The face immersion significantly increased SD(RR) and CV(RR) (P < 0.05), and increased RR(mean) (P < 0.05) at 20 breaths·min-1. Face immersion itself had no effect on oxygen uptake, tidal volume, end-tidal O2 and CO2 partial pressures. The diving reflex without breath-holding increased the heart rate variability, indicating that face immersion alone increases vagal activity.
AB - We examined whether the diving reflex without breath-holding (face immersion alone) increases vagal activity, as determined by heart rate variability. A group of 15 men [mean age 20 (SD 3) years, height 172 (SD 5) cm, body mass 68 (SD 9) kg] performed 12 trials at various breathing frequencies (5, 10, 15, 20, 30 breaths·min-1 and uncontrolled breath) with or without face immersion. The R-R intervals of the ECG and gas exchange variables were recorded during the 2 min of each trial. The subjects immersed their faces in 8-10°C water while breathing through a short snorkel. The subject sat in the same position either with or without face immersion. The mean R-R interval (RR(mean)), standard deviations (SD(RR)) and coefficient of variance (CV(RR)) of the R-R interval were calculated from the R-R intervals during 30-130 s. The face immersion significantly increased SD(RR) and CV(RR) (P < 0.05), and increased RR(mean) (P < 0.05) at 20 breaths·min-1. Face immersion itself had no effect on oxygen uptake, tidal volume, end-tidal O2 and CO2 partial pressures. The diving reflex without breath-holding increased the heart rate variability, indicating that face immersion alone increases vagal activity.
KW - Bradycardia
KW - Breathing frequency
KW - Diving reflex
KW - Heart rate fluctuation
KW - Human
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U2 - 10.1007/s004210050267
DO - 10.1007/s004210050267
M3 - Article
C2 - 9367278
AN - SCOPUS:0030703184
SN - 1439-6319
VL - 76
SP - 394
EP - 399
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
IS - 5
ER -
