The cold and dry air have become a tough season. The sun goes down quickly, and the nights feel longer. I feel like I'm getting enough sleep for that amount, but it seems that the opposite is actually the case. In particular, we often hear people say, "It's cold and I can't sleep well" or "It's hard to get out of bed in the morning."
Yukako Nishikawa, a sleep researcher, also said, "Winter is the season when it is difficult to get a good night's sleep." We asked for specific reasons and countermeasures.

“Cold” and “sun” are the major causes of shallow sleep in winter

“When people fall asleep, they enter rest mode by releasing heat from their hands and feet and lowering their core body temperature. If you do, you will not be able to go into rest mode properly, so you will have trouble falling asleep, or the quality of your sleep will deteriorate, making it difficult to wake up,” says Nishikawa.

This seems to be the case, especially during winter. One of the reasons is "cold".
“The key to lowering your body temperature at night is how to raise your body temperature during the day. Ideally, there should be a temperature difference of about 1 degree between day and night. , Some people find it difficult to raise their body temperature.The smaller the temperature difference, the more difficult it is to fall asleep.”
This is especially true for people who are sensitive to cold or who are less active during the day.

And the shortness of daylight hours is also related to the quality of sleep.
“During the winter, the amount of sunlight is shorter and the amount of sunlight is less. Sunlight is essential for this.When we are stimulated by light, we secrete a hormone called "serotonin."This "serotonin" is called "melatonin," which is called the sleep hormone when the sun goes down. It is transformed into a drowsy, deep sleep.”

Sunlight can also affect your mental health.
"When you're in a negative mood, exposure to sunlight makes you feel better, but not enough sunlight can make you irritable and depressed. These feelings can lead to stress. It can lead to sleep disturbances.”

What are some unexpected behaviors that you should be aware of for a good night's sleep in winter?

“The time and amount of dinner is also important. Ideally, you should finish your meal two to three hours before you go to bed. If you wake up feeling hungry or don't want to eat breakfast, it's possible that you ate dinner too late or too much."
The key is to limit alcohol consumption to 2-3 hours before bedtime.
“Being too strict can also make life boring, so on days when you want to have fun, you can enjoy eating and drinking until late at night.

In addition, the "body warming" goods that I think are good are disturbing my sleep!
"I don't recommend electric blankets. They don't cool down your core body temperature, and many of them are made of materials such as acrylic and polyester, so your body gets stuffy easily. A hot water bottle warms up cold feet. It's effective for sleeping, but it also makes it harder to turn over after falling asleep.
Also, "socks while sleeping" to warm your cold feet seems to have the opposite effect.
"They can't dissipate heat to lower their core body temperature. As a result, they sleep poorly."

And even those with a high sense of beauty should be aware of vigorous exercise at night. “Hard exercise at night, such as tennis at night, running, or people who commute by bicycle for health reasons, makes the sympathetic nervous system dominant.It is difficult to fall asleep smoothly because the parasympathetic nervous system, which controls sleep, cannot be switched well. Or my sleep becomes shallow."
For those who want to incorporate a nighttime exercise routine, yoga and stretching, which have a relaxing effect, will lead to a good night's sleep.

5 articles for good quality sleep that you want to keep in mind from today

1. Expose yourself to sunlight as soon as you wake up in the morning
"The sleep hormone 'melatonin' is secreted 14 to 16 hours after being exposed to sunlight. By basking in the sun in the morning, 'melatonin' is more likely to be released at night."

2.Increase the amount of activity during the day as much as possible 
"When it's cold, people tend to stay at home. If you don't have enough activity, you'll get tired and your body will think you don't need rest, so you won't be able to get enough deep sleep. Let's go out and get moving. You can kill two birds with one stone by being bathed in sunlight."

3. Soak in the bathtub as much as possible
"At least one hour before bedtime, soak in a 38-40 degree hot tub for 10-15 minutes. Keeping your body warm will help lower your core body temperature, making it easier to fall asleep. If you keep doing this every day, you will sleep deeper. It's especially recommended for people who tend to get cold feet."

4. Utilize the futon dryer
“It may be a good idea to warm your bedding with a futon dryer before going to bed.

Five. tidy up the room
“It is recommended that the room temperature in the bedroom in winter is 20°C or higher and the humidity is 50 to 60%. It is said that the rate will be low.It is important to be aware of the range that does not disturb sleep according to the season."

summary

When you get a good night's sleep, you feel great when you wake up. You can have a delicious breakfast, which helps reset your body clock. For your physical and mental health, please review your winter sleep.
In addition, vitamin C is said to help support sleep. Please be conscious of continuing to take vitamin C efficiently.


Yukako Nishikawa
Sleep researcher, Cello trainer. Vice President and Representative Director of Showa Nishikawa and Director of Muatsu Three Lab. He is active in a wide range of fields, including bedding development, sleep goods development, sleep-related lecturers, sleep event supervision, sleep environment supervision for hotel rooms in Japan and overseas, media contributions, and corporate lectures. The book "Strongest Sleep" (SB Creative) is now on sale.

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