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It’s no exaggeration to say that sleep determines how your brain and body function!
Most of the stress, fatigue, headaches, and stiff shoulders that many modern people experience are caused by hormonal imbalances and autonomic nervous system dysfunction.
However, simply lying in bed and falling asleep without thinking is not enough. There are several key points to ensure you get the best sleep. This article will introduce the most important of these points.
The first 90 minutes of sleep are crucial!
What becomes important is how to deepen the non-REM sleep (a state where both the brain and body are asleep) that occurs in the first 90 minutes immediately after falling asleep. During this time, a lot of sleep pressure (the desire to sleep) is released, so ensuring a high-quality 90 minutes is essential.
This improves the quality of subsequent sleep, allowing you to achieve the best sleep. If deep sleep occurs at the beginning of sleep and sleep pressure is released, deep sleep will not occur in the early morning, and you will wake up naturally feeling refreshed.
The Relationship Between Non-REM Sleep and Hormones
By getting a solid 90 minutes of non-REM sleep at the beginning, your autonomic nervous system can be regulated. Furthermore, growth hormone, which is secreted in significantly large amounts during this time, plays an important role for adults in cell proliferation, normal metabolic promotion, and anti-aging care.
Skin is also affected by growth hormone and is constantly being replaced with new skin, so good sleep is garnering attention for its benefits to beauty.
Growth hormone is a special sleep-dependent hormone, and its secretion amount is overwhelmingly proportional to the quality of non-REM sleep in the initial stages of sleep. If you are awake during the hours you would normally be sleeping, it becomes harder for it to be secreted.
It is often said that a large amount is secreted when you fall asleep between 10 PM and 2 AM, but it doesn't matter what time you go to bed. However, if deep sleep does not occur when you fall asleep, it will not be sufficiently secreted.
In other words, the quality of the first 90 minutes is crucial, so there is no need to be particular about the time you go to sleep. However, if you go to sleep at the same time every day, your biological rhythms, such as body temperature, will be regulated, making it easier to achieve deep sleep when you fall asleep.
What is the relationship between falling asleep and body temperature?
The two types of human body temperature
To improve your ability to fall asleep, a "body temperature switch" is important.
The human body has two types of temperature: skin temperature, which is the temperature of the surface of the hands and feet, and core body temperature, which is the temperature inside the body.
Heat is produced by the movement of muscles, fat, and internal organs, and while awake, core body temperature is typically up to 2 degrees higher than skin temperature.
The reason your hands and feet feel warm when you're sleepy is because, during the onset of sleep, your skin temperature rises, and heat is released through the capillaries in your hands and feet, which lowers your core body temperature.
By turning these body temperatures on and off at the start of sleep and reducing the difference between the two temperatures, you can fall asleep smoothly.
Bathing is effective for the body temperature switch
Essential for this "body temperature switch" is taking a bath 90 minutes before bedtime. Soaking in a 40-degree bath for 15 minutes temporarily raises your core body temperature by about 0.5°C.
After that, it takes about 90 minutes for your body temperature to return to its original state, but core body temperature has the characteristic of dropping by the amount it rose. From that point on, your core body temperature will drop lower than when you don't bathe, and the difference with your skin temperature will narrow.
Therefore, by taking a bath 90 minutes before bed, you can fall asleep smoothly. Both bathing and exercise are often effective for falling asleep, but the timing and degree are important; if done incorrectly, they can be counterproductive.
To sleep soundly at night, preparation is needed from the morning.
Furthermore, sleep and wakefulness are two sides of the same coin, and good wakefulness leads to good sleep. Therefore, it is important to activate a "wakefulness switch" when you get up to promote good sleep.
Many people use the snooze function on their phone alarms, but the snooze function is not conducive to a good awakening.
Instead, set a time-window alarm that utilizes your sleep cycle. This method involves setting two alarms: one for your ideal wake-up time and another 20 minutes earlier.
The first alarm should be very quiet and short, and the second should be loud. In the early morning, the duration of light sleep increases, and the sleep cycle shortens, so setting two alarms significantly increases the chance of waking up during an easy-to-wake period.
And, as soon as you wake up, open the curtains.
Humans operate on a circadian rhythm, but their intrinsic period is longer than 24 hours, and if left unchecked, it tends to shift later.
Exposure to morning light, regardless of the weather, resets your internal clock.
Even indoors by a window, you can get enough light to reset your internal clock.
Take a moment to review your lifestyle. Diet and exercise are also essential for good sleep.
By consciously making small changes day by day, you can achieve the best sleep.
