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Many people have busy evenings with various plans such as drinking parties, overtime, spending time with friends, dates, studying, lessons, and going to the gym, which can lead to inconsistent bedtimes. To achieve high-quality sleep, it's recommended to try and fix your bedtime as much as possible, even with all these individual plans. This time, we'll explain why.
Recommendation to establish a "Fixed Bedtime"
Good sleep habits lead to deep sleep (during the first NREM sleep), which helps relieve fatigue and remove brain waste. By fixing your bedtime, deep sleep will occur immediately after falling asleep.
However, due to drinking parties, overtime, private errands, etc., it can be difficult to go to bed at the same time every day. Considering these factors, it is advisable to establish your basic bedtime as a "fixed bedtime."
Also, you might have experienced difficulty sleeping even when you try to go to bed early because you have an early start the next day. This is likely due to being strongly affected by the "forbidden zone," where the brain resists sleep just before bedtime. It's a strange phenomenon, but it's generally most difficult to fall asleep from just before your usual bedtime until about two hours prior.
Therefore, when you have an early start the next day, if you go to bed at your usual time and wake up earlier, your sleep duration will be slightly shorter, but you'll fall asleep more easily, get deep sleep, and maintain sleep quality.
Benefits of Regular Habits
Regular habits are important for both health and mental stability. The same applies to sleep, which accounts for one-third of our lives. The quality of sleep significantly impacts the likelihood of developing diseases such as cancer and lifestyle-related illnesses, mental health conditions, and dementia, as well as influencing performance during waking hours.
Irregular sleep habits can easily lead to feeling unwell, such as difficulty falling asleep, not feeling rested even after sleeping, or persistent fatigue.
By creating a healthy sleep rhythm, you can suppress sympathetic nervous system activity, promote a smooth drop in body temperature, and quickly and more deeply induce the most important first NREM sleep, known as the "golden 90 minutes." During this initial deep NREM sleep, or "golden 90 minutes," the secretion of growth hormone, crucial for metabolism, is promoted, immunity is boosted, and important sleep functions such as the removal of brain waste are carried out.
To secure these "golden 90 minutes," it's advisable to set your "fixed bedtime" considering various potential daily plans. Since it's a "fixed" time, even if you occasionally go to bed later than usual, it's fine as long as you go to bed at that fixed time the next day. The key is to establish a habit of sleeping at your fixed time.
Why you can't sleep when you try to go to bed earlier than usual
For example, if you need to wake up an hour earlier than usual, trying to go to bed an hour earlier, based on your wake-up time, will make it harder to fall asleep due to the forbidden zone effect explained earlier. However, if you go to bed at your usual time and wake up an hour earlier than usual, based on your bedtime, you can fall asleep smoothly, and the first NREM sleep, the "golden 90 minutes," will occur as usual, thus making it easier to maintain sleep quality. We recommend establishing a sleep habit centered around a fixed bedtime.
If you absolutely need to go to bed earlier, there are methods such as managing your body temperature by taking a bath, adjusting lighting, or paying attention to pre-sleep activities. However, it is ultimately more purposeful to follow your natural physiological processes.
※1: (a 20 minute day)
