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Are you getting the best sleep possible? Many people probably struggle with something, whether it's difficulty falling asleep, feeling sleepy or tired even after a full night's rest, waking up in the middle of the night, not waking up refreshed, feeling sleepy often during the day, or severe snoring.
Sleep: A Common Concern for Many
While we pay attention to nutritionally balanced meals for health, training and stretching methods for diet, diet products, cosmetics for beauty, and study methods and memorization techniques for improving our minds, most people probably don't pay much attention to "sleep," which they do every single day.
Furthermore, even if you try to gather information to solve your problems, there is a lot of inaccurate or incorrect information out there, and as a result of implementing a sleep improvement program based on wrong information, it is often the case that things don't change, or even worsen.
Therefore, we will introduce "The 10 Best Sleep Methods" recommended by Dr. Seiji Nishino (Professor at Stanford University School of Medicine, Director of the Stanford University Sleep and Circadian Neurobiology Laboratory), who heads the sleep research laboratory at Stanford University, the mecca of sleep research.
What is the Best Sleep?
By the way, what do you think is the best sleep? The best sleep is "ultimately high-quality sleep" that brings your "brain, body, and mind" into the best condition. Please note that it is not about the length of sleep.
While too little sleep is not good for your body, research also shows that too much sleep is not good either. Moreover, sleep and wakefulness (performance) are two sides of the same coin; if you get the best sleep, you will achieve the best wakefulness (performance).
Conversely, poor sleep leads to poor wakefulness (performance). Spending one-third of your life sleeping is a crucial preparation/cleanup time for spending the remaining two-thirds of your life actively, and thus, it can be said to be extremely important.
In other words, it is no exaggeration to say that those who master sleep master life. "What determines the quality of sleep?" The quality of sleep is greatly influenced by the first 90 minutes of sleep. The key is how deeply you sleep during those initial 90 minutes.
Below, we will introduce sleep methods for an entire day (Morning Chapter, Afternoon Chapter, Evening Chapter). Please try them starting today.
-Morning-
Mornings mainly promote wakefulness to enhance the day's activity.Rule 1: Fix your wake-up time and set two alarms
Set the second alarm for 20 minutes after the first. The key is to set the first alarm to be "very quiet and short."
For example, if you go to bed at 11 PM and wake up at 7 AM, you would set alarms for 6:40 AM and 7:00 AM. It's okay if you don't wake up at the first alarm.
If you're forced to wake up during deep sleep, you'll feel groggy and your mind won't be sharp. To wake up refreshed, you need to wake up during light non-REM sleep or REM sleep, and in the morning, non-REM sleep is shorter while REM sleep is longer.
In a healthy sleep pattern, REM sleep and light non-REM sleep naturally increase in the early morning, so even if you don't wake up to the first alarm, you can wake up to the second alarm.
Click here for details on Rule 1!
Rule 2: Bask in the sunlight
The first thing you should do when you wake up is open your curtains and bask in the sunlight.
The human body clock is slightly longer than 24 hours, and if left unchecked, the rhythm tends to shift later. However, by exposure to morning light, the body clock is reset, and this shift can be adjusted.
So, the first thing you should do when you wake up is open the curtains in your bedroom and bask in the sunlight. Exposure to light signals to your body that it's morning, and your body clock is reset every morning.
Sunlight has awakening and mood-boosting effects, and there are many benefits to getting sunlight during the day.
Also, regardless of whether it's sunny, rainy, or cloudy, there's enough light, so it's good to be active outdoors as much as possible during the day.
Conversely, avoiding strong indoor lighting at night, especially before bed, and not suppressing the secretion of melatonin, which is involved in sleep and rhythm regulation, with light, will lead to good sleep and a refreshed awakening.
Click here for details on Rule 2!
Rule 3: Eat a breakfast that emphasizes chewing (warm soup is even better)
For breakfast, actively eat foods that require a lot of chewing. Eating breakfast has many benefits.
Eating a breakfast that emphasizes chewing promotes wakefulness through sensory nerve stimulation and the act of chewing, and it also provides energy for the start of the day.
Furthermore, since fat burns most easily in the morning, eating breakfast can be more effective in preventing obesity than skipping it, and like exposure to sunlight, it has a body clock reset effect. Chewing can also improve memory, and it can create a sense of rhythm for the day, and so on. It's full of good things.
To enhance chewiness, you can make it more effective by cutting ingredients into larger pieces or mixing highly nutritious multi-grain rice with white rice.
Also, warm soup can further enhance wakefulness. Wakefulness requires an increase in the core body temperature of organs and other internal parts of the body, but warm soup slightly raises core body temperature, making it easier to wake up.
-Afternoon-
It's easy to get sleepy around noon, so here are some tips on how to deal with it.
Rule 4: Take a power nap (15-30 minutes)
You might feel sleepy during the day (especially in the early afternoon), but if you have a little extra time when you feel sleepy, it's recommended to take a power nap according to your sleep pressure.
A power nap is a short nap of about 15 to 30 minutes. It has been known that power naps refresh and restore performance, but recently, it has become a hot topic that power naps also reduce the risk of dementia (by about 1/7) and diabetes, as well as other diseases.
However, more sleep is not always better. Some reports indicate that napping for more than an hour can double the risk of dementia.
If you take a nap for several hours, it not only disrupts your sleep rhythm but also indicates that you have accumulated sleep debt, so you need to re-evaluate your daily sleep habits.
Click here for details on Rule 4!
Rule 5: Hold something cold or wash your hands and face with cold water
In Rule 4, I recommended a power nap as an action to follow sleep pressure, but there are often situations where you can't sleep.
As another way to relieve sleep pressure and wake up, try holding something cold like a plastic bottle or washing your hands and face in the restroom. This cool stimulus and decrease in skin temperature are effective in breaking through sleepiness.
Other effective methods include chewing refreshing gum like mint or consuming caffeinated drinks and foods (e.g., coffee, tea, GABA-containing chocolate).
Also, generally, regardless of whether you've had lunch, there's a phenomenon called the afternoon dip, where you tend to get sleepy around 2 PM due to your biological rhythm.
Therefore, if this tendency is strong, avoiding important things (meetings, presentations, etc.) around 2 PM can help prevent mistakes.
However, feeling sleepy often during the day is due to accumulated sleep debt. To improve daytime sleepiness, it is important to resolve sleep debt.
Click here for details on Rule 5!
-Evening-
From here, we will introduce important points to keep in mind as preparation for falling asleep.
Rule 6: Eat chilled tomatoes (foods that lower core body temperature)
First and foremost, it's important to eat a nutritionally balanced diet. A skewed diet or overeating can lead to a lack of essential nutrients, hindering ideal hormone secretion and tissue regeneration, and can also result in indigestion, obesity, alcoholism, and even lifestyle diseases, so caution is advised.
Additionally, sleep requires raising skin temperature and lowering core body temperature, so it's recommended to eat foods that have a cooling effect on the body. Eating these cooling foods chilled will make them even more effective.
Generally, vegetables that grow in summer, such as tomatoes and cucumbers, are said to have a cooling effect on the body. Furthermore, if you skip dinner for dieting, a hormone called orexin, which promotes appetite and wakefulness, will be secreted and inhibit sleep, so try to eat at least a light dinner.
Also, when eating, aim to finish at least 2 hours before bedtime to allow for digestion and absorption.
Click here for details on Rule 6!
Rule 7: Bathe 90 minutes before bedtime or take a shower if going to bed soon
Regarding bathing, it is recommended to finish bathing 90 minutes before bedtime. There are two types of body temperature: skin temperature and core body temperature. For sleep, it is important that the difference between skin temperature and core body temperature narrows (within 2°C), meaning that skin temperature ultimately becomes higher and core body temperature becomes lower.
To achieve this, it is necessary to first raise both skin and core body temperatures, and then dissipate heat to lower core body temperature, and bathing is the most effective way to do this.
The 90-minute period is the time it takes for the core body temperature, which temporarily rises during a normal bath, to return to its original temperature. After returning to its original temperature, the body temperature continues to drop, naturally making you feel sleepy.
Generally, it is good to take a half-body bath at about 40 degrees Celsius for 10-15 minutes, but carbonated baths or sodium baths can enhance the effect even more.
Carbonated baths are recommended as they have no downsides, as they do not cause fatigue such as dizziness after bathing. If you don't have much time until bedtime, take a shower to avoid an increase in core body temperature.
Also, foot baths are extremely effective and can be expected to have similar effects to bathing.
Click here for details on Rule 7!
Rule 8: Eliminate smartphones (electronic devices)
We tend to touch our phones and PCs right before bed, but exposure to short-wavelength blue light increases alertness and suppresses the secretion of "melatonin," known as the sleep hormone, making it harder to sleep. Therefore, refrain from using smartphones, PCs, and other electronic devices (those that use LEDs) before bed.
Even if you set your phone to night mode to reduce blue light, operating your smartphone will stimulate your brain, preventing it from preparing for sleep.
Opening just one annoying or worrisome email can keep you awake until morning. Also, Japanese homes and restaurants generally tend to have overly bright lighting, so switching to indirect lighting with warm colors can create a more sleep-conducive environment.
Some people sleep with a bedside lamp on, but experiments show that even typical night light (around 10 lux) can inhibit melatonin synthesis. Therefore, it is appropriate to use a footlight or a small indirect light placed at a distance.
Click here for details on Rule 8!
Rule 9: Fix your bedtime
With good sleep habits, you can achieve deep sleep in the first 90 minutes of falling asleep, which helps you recover from fatigue and eliminate waste from your brain. Fixing your bedtime ensures that deep sleep occurs immediately after falling asleep.
However, due to social gatherings, overtime work, or personal commitments, it may be difficult to go to bed at the same time every day. Taking these into account, it's a good idea to set a "regular bedtime" for yourself.
Also, even if you try to go to bed earlier because you have an early start tomorrow, you've probably experienced difficulty falling asleep. This is highly likely due to the brain's rejection of sleep just before bedtime, known as the "Forbidden Zone."
It's a curious phenomenon, but the period from just before your usual bedtime until about two hours before is considered the most difficult time to fall asleep. Therefore, when you have an early start the next day, if you keep your bedtime as usual but wake up earlier, even if your sleep duration is slightly shorter, you will find it easier to fall asleep and achieve deep sleep, thus ensuring sleep quality.
Click here for details on Rule 9!
Rule 10: Sleep barefoot & take off your socks
People who suffer from cold feet often try to sleep with socks on because they can't sleep due to the cold, but this is counterproductive. Avoid sleeping with socks on.
At least take them off before you go to bed. To fall asleep, your skin temperature needs to rise to release heat from your hands and feet, but wearing socks traps heat in your feet, preventing heat from escaping.
If you have cold feet, warm them sufficiently with massage or by wearing socks, then take off your socks and get into bed. A "foot bath" is even more effective than socks and can be expected to have similar effects to a full bath. Unlike a full bath, it approaches heat dissipation rather than raising core body temperature, so it is recommended to do it right before bed.
Also, a lack of daily exercise, an unhealthy diet, excessive smoking or drinking can lead to poor circulation and coldness, so it's important to address the root causes of cold feet.
Click here for details on Rule 10!
If you are struggling with sleep, try incorporating the 10 rules above first. If your symptoms are severe or you don't see much improvement, consult a sleep specialist immediately.
