A joint research group from Akita University and others conducted an experiment to find out whether bathing in a hot spring really helps you sleep better.As a result, I found that I slept deeply when I entered the chloride spring and the carbonate spring.Ehime University, Tohoku University, Nagoya University, and Nagoya Institute of Technology are participating in the research.
Bathing helps people fall asleep faster and sleep better, but the effect of hot springs, which have been used to recover from fatigue and improve health, on sleep is unknown.Therefore, the research group investigated the effects of chloride springs and artificial carbonated springs (because natural carbonated springs are scarce) in promoting sleep.
Sleep was evaluated in eight healthy male subjects under the conditions of chloride spring, artificial carbonated spring, normal bath, and no bath. Bathe before going to bed in any condition for 8 times. Soak in hot water at 4°C for 40 minutes from 22:15 and go to bed from midnight to 0:7.They wore a simple electroencephalograph and a thermometer while sleeping, and answered a questionnaire about sleepiness and fatigue before and after taking a bath and when waking up.
As a result, they slept better when they took a bath than when they did not, especially when they entered hot springs, chloride springs (here, Akita Onsen Satomi), and artificial carbonated springs.
Even with hot water of the same temperature, when you enter a hot spring with a strong heating effect due to salt and carbon dioxide gas, the heat intake is large, and the deep body temperature rises greatly after bathing.In addition, when the increase in core body temperature was strong, heat dissipation progressed as a reaction, and the core body temperature decreased 90 minutes after bathing compared to when not bathing.A drop in core body temperature is known to induce drowsiness and deep sleep.As a result, deep sleep appeared in the hot spring bath.In addition, since chloride springs leave a feeling of fatigue after bathing, artificial carbonated springs are said to be best for frail elderly people.
The results of this study are an important finding that proves the efficacy of hot springs for sleep, and will be useful for treating insomnia and utilizing hot springs in the Akita region.
Paper information:[Journal of Physical Therapy Science] Changes in sleep profile on exposure to sodium chloride and artificially carbonated springs: a pilot study
