Just changing the way you bathe can dramatically help you fall asleep more easily.
Bathe 2 hours before you want to go to bed, and bathe at 40°C for 30 minutes. However, the bath should warm the body to the core, so if you feel faint, shorten the time. Bathing temporarily raises the body temperature, and the subsequent drop in deep body temperature reduces the difference between the skin temperature and the body temperature, making it easier to sleep.
The research paper, ヒトの体温調節と睡眠, is cited and referenced.
Deep body temperature tends to be higher during the day and lower at night in humans who are active during the day due to circadian rhythms.
In addition, a high deep body temperature stimulates enzymatic reactions in the body to produce energy. In other words, the body temperature is raised in order to be active.
Conversely, when the deep body temperature is low, enzymatic reactions are suppressed, metabolism is reduced, and the whole body, including the brain, is in a resting state.
The figure below shows that the lower the deep body temperature at the time of falling asleep, the shorter the time it takes to fall asleep (sleep latency).
The fluctuations that occur in the 24-hour cycle of deep body temperature are controlled by heat dissipation from the skin. In other words, sleep is induced when the deep body temperature falls due to heat dissipation. This is the reason why “babies warm hands and feet” are a sign that they want to sleep.
The following article cites and references the research article Warm feet promote the rapid onset of sleep.
Following this finding, it has been reported that people who are cold and prone to cold hands and feet take longer to fall asleep. It can be interpreted that cold people with low peripheral skin temperatures are unable to dissipate heat and lower their deep body temperature, which interferes with the transition to sleep. The reason it is difficult to sleep when the temperature is high or the humidity is high is because it is difficult for heat to escape from the skin.
The following article cites and references the research article Sleeping with an Electric Blanket: Effects on Core Temperature, Sleep, and Melatonin in Young Adults.
Furthermore, the environmental temperature during sleep is closely related to the quantity and quality of sleep. It has been reported that keeping the furniture temperature high during sleep with electric blankets, etc., causes more awakenings in the middle of the night and makes sleep more unstable. When heat dissipation is disturbed, deep body temperature is not lowered sufficiently, and sleep becomes unstable.
This close relationship between body temperature and sleep has led to the idea of ways to promote sleep by taking a bath or footbath before bedtime. It has been reported that bathing under the right conditions can improve sleep.
The following article cites and references the research article Cold feet and prolonged sleep-onset latency in vasospastic syndrome.
A study has investigated bathing to mid-chest at 40°C for 30 minutes two hours before bedtime. The figure below shows a comparison between the previous (standard) and a 30-minute 40°C bath up to mid-chest two hours before bedtime. The upper side of the figure shows sleep efficiency and the lower side shows mid-wake data. Sleep efficiency can be calculated by dividing the time spent asleep by the time spent lying on the bed. In other words, the shorter the time it takes to fall asleep, the higher the sleep efficiency. The time of mid-awakening is the time when you fell asleep but woke up in the middle of the sleep. The shorter the time of mid-awakening, the better, or rather, it is best to have no mid-awakening itself. The figure shows that bathing under these conditions increases sleep efficiency. In other words, it was found to shorten the time it takes to fall asleep, and furthermore, to decrease the time of mid-awakening.
The following article cites and references the research article Passive body heating ameliorates sleep disturbances in patients with vascular dementia without circadian phase-shifting.
There is a report of an experiment in which 6 women with fibromyalgia were given a 36°C bath from 6 to 8 pm, 5 times a week for 3 weeks. Results showed that on the first day, REM sleep (shallow sleep) latency was shortened and deep sleep was increased; by the end of 15 sessions, waking time was reduced, sleep latency was shortened, REM sleep latency was shortened, sleep efficiency was increased, and deep sleep was increased. Furthermore, these effects persisted in a study conducted three weeks after the end of the experiment.
Some studies have found benefits from foot bathing. After a 6-month subjective sleep evaluation of 18 female patients undergoing chemotherapy for gynecological tumors, who were divided into two groups: those who took nightly foot baths at 41-42°C for 20 minutes each night and those who did not, subjective sleep quality was improved in the group that took foot baths at 41-42°C for 20 minutes each night.
These results suggest that bathing with a transient increase in skin temperature and deep body temperature had a stimulating effect on the temperature center and a subsequent increase in blood flow in skin peripheral blood vessels, resulting in increased heat dissipation and promoting sleep.
In addition, carbonic acid bath salts seem to have a vasodilating effect, which is said to further enhance the effects of bathing.
I actually did it.
In fact, I even tried it with my 3 year old: we have a bath at 40 degrees Celsius and go in together. I give him a toy to soak for a long time, but he can’t soak for very long. He didn’t like it because it made him run over.
The time spent in the bathtub is probably about 10 minutes. The time we were soaked up to our shoulders is about 3 minutes. It was about 30 minutes before we started taking off our clothes, got out of the bath and put on our clothes.
The child’s body was red, so I think his body was warm just after he got out of the bath.
I got out of the bath and felt drowsy an hour and a half to two hours later. It was only 8:30pm at that time. However, 2 hours later I felt that the child was not behaving any differently than usual.
The child’s small size may have caused him to dissipate heat more quickly, unable to maintain a deep body temperature. I thought that perhaps he was feeling drowsy about an hour after bathing.
I know it varies from person to person, but it has worked for adults, so give it a try. Oh, and don’t forget to stay hydrated!
In addition to bathing, there are other ways to do this
Besides bathing, other options include foot baths, mist saunas, and drinking ice slurries.
Effects of foot baths
The following article cites and references the research article Effects of Bathing and Hot Footbath on Sleep in Winter.
In an experiment, young women wearing long-sleeved pajamas in a 10°C environment were compared after taking a 20-minute bath in 40°C water, a 30-minute foot bath in 42°C water, and no bath. Compared to no bathing, a 20-minute foot bath in 40°C water and a 30-minute foot bath in 42°C water shortened the latency to fall asleep and increased sleep stage 3, but decreased sleep stage 4, so there was no effect in terms of slow wave sleep (deep sleep). However, there does not seem to be a significant difference between a 20-minute foot bath in 40°C water and a 30-minute foot bath in 42°C water, so it can be said that a foot bath has a sufficient effect.
Benefits and advantages of mist sauna
Mist sauna bathing, which warms the whole body at low temperature and high humidity and has been developed in recent years and installed in an increasing number of homes, showed no difference from whole-body bathing.
Mist saunas are likely to be useful in nursing care environments, etc., because the low temperatures are less stressful on the body.
Ice Slurry Effects
Ice slurries are more fluid than ice and have more cooling capacity than water, effectively cooling the body. It is used to prevent heat stroke, but can also promote sleep on tropical nights.
The following article cites and references the research article アイススラリーを利用した睡眠環境の改善
Comparisons were made between those who ingested ice slurries before sleep and those who did not. The results showed no significant difference in sleep duration. However, the higher bedtime temperatures resulted in a longer period of deep sleep when the ice slurry was consumed.
コメント