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Have you ever thought, "I'll go to bed early and get rid of this fatigue?"
For example, when you're tired from a weekend of fun and have to work on Monday, many people have probably tried to go to bed early, haven't they?
"The more I sleep, even 10 or 12 hours, the more refreshed I feel the next day, and it's good for my health, right?"
Certainly, the number of hours you sleep is an important consideration.
However, the difficult thing about sleep is that it's not always better to simply sleep as much as you can.
This time, we will focus on the quality of sleep and explain it. We will also touch on questions about sleep duration and methods for getting good quality sleep.
1. Is good quality sleep simply sleeping for a long time?
Some people may have experienced feeling unrefreshed even after sleeping for 10 hours.
That's right. While sleep duration is important, the quality of sleep is equally, if not more, important. In modern society, few people can maintain a regular lifestyle and consistently get enough sleep every day.
Whether it's overtime work or studying for exams, don't we often cut back on sleep? Also, some people may feel that they can't sleep as well as they used to, or that they don't feel refreshed even after sleeping.
Sleep is greatly influenced by one's living environment and age, so let's explain those points.
1-1. Good quality sleep ≠ long sleep duration
Self-assessment is crucial when it comes to sleep. It's difficult to definitively say that sleeping a certain amount of time will guarantee feeling refreshed the next day. Your physical and mental state at the time can significantly alter your sleep experience.
Let's look at some interesting data related to sleep.
There was a study where 10 healthy individuals were forced to stay in bed for 14 hours. On the first and second days, they slept for nearly 13 hours, but after three weeks, their average sleep settled at 8.2 hours.
From this result, we can conclude that 8.2 hours was the amount of sleep they needed.
Regarding whether longer sleep duration is always better, there are also several research data points.
According to a large-scale study on "sleep duration and mortality risk" conducted and published by Nagoya University in 2004, the average sleep duration was 7.5 hours for men and 7.1 hours for women.
And it was reported that the lowest mortality rate 10 years later was among those who slept for approximately 7 hours.
From this, it can be said that it is not necessarily true that the longer the sleep duration, the better.
1-2. Necessary sleep duration for good quality sleep
So, you're asking, "How many hours should I sleep?"
The amount of sleep needed varies from person to person, but I believe 6-7 hours a day is necessary.
Again, the necessary sleep duration varies from person to person, and it is difficult to define an absolute amount that everyone must get.
However, if you are currently sleeping less than 6 hours, I encourage you to try extending your sleep by even 30 minutes and see what changes you experience.
There are some people who can function perfectly well with extremely short sleep durations. These people are known as "short sleepers."
However, it has been found that the reason they can maintain such a sleep rhythm lies in their genetics. This means that even if a typical person tries hard to reduce their sleep, they cannot fundamentally reduce it by a large amount.
2. Poor quality sleep can lead to lifestyle diseases
It is often said that lack of sleep reduces efficiency in daily work and other activities.
Also, it is true that lack of sleep often leads to a lack of attention and an inability to make appropriate decisions in driving and various situations.
However, it has been found that lack of sleep is also closely linked to physical illnesses.
If you don't sleep, the secretion of insulin, a hormone that lowers blood sugar, deteriorates, leading to high blood sugar and diabetes.
- Lack of leptin, a hormone that suppresses overeating, leading to weight gain.
- Increased ghrelin, a hormone that stimulates appetite, leading to weight gain.
- Sustained sympathetic nervous system tension, leading to high blood pressure.
- Increased risk of mental instability, depression, and anxiety disorders.
The above points have been highlighted, indicating that sleep deprivation increases the risk of lifestyle diseases.
Sleep is closely related to health, so it's important not to underestimate sleep deprivation.
3. Sleep problems increase with age
As the body ages, various functions decline.
When it comes to sleep, you tend to go to bed earlier and wake up earlier compared to when you were younger. This is because the body's biological rhythm shifts forward with aging.
Therefore, as you get older, you tend to go to bed earlier and wake up earlier.
This is something that can happen to everyone with age, so if the symptoms are not extreme, it can be considered a result of aging.
As we age, our ability to regulate body temperature also declines. As a result, our bodies are not adequately prepared for sleep, and we cannot achieve deep sleep.
This is why sleep becomes lighter, and even small noises can wake us up. Chronic illnesses can also be a cause of difficulty sleeping.
Heart disease can make it difficult to breathe when lying down, and chronic inflammatory pain from conditions like rheumatoid arthritis can also make it hard to sleep.
Additionally, frequent urination at night due to benign prostatic hyperplasia or overactive bladder can also be a cause of restless sleep.
As you can see, it can become increasingly difficult to get a satisfying amount of sleep as we age.
4. Time is important, but quality is also important! Aim for good quality sleep by following these 3 rules.
Some of you reading this might be thinking, "I'm too busy to get that much sleep."
Also, as mentioned earlier, some people may not be able to get enough sleep as they get older, even if they try.
In such cases, it's perfectly fine to focus on improving the quality of your sleep. It would be ideal if you could both get enough sleep and improve its quality, but that's often difficult.
This time, I'd like to introduce three rules to improve sleep quality.
Please try them out, and I hope you'll feel "I slept well today" when you wake up, even if it's just a little bit.
4-1. Keep your wake-up time consistent
The first is to keep your wake-up time consistent.
In modern society, it can be difficult to maintain a consistent sleep schedule. At the very least, try to keep your wake-up time consistent to avoid disrupting your internal clock.
Many people might have a consistent wake-up time on weekdays, but there are probably some who tend to sleep in on weekends.
If your wake-up time shifts on weekends, you might find your mind isn't sharp and you feel unwell when you wake up on Monday morning.
By keeping your wake-up time consistent, your biological rhythm will stabilize, and melatonin, the hormone that promotes sleep at night, will be secreted appropriately!
4-2. Bask in the sun in the morning
The second is to consciously expose yourself to sunlight in the morning.
Sunlight can be considered the strongest alarm clock, resetting our internal clock.
By getting enough sunlight in the morning, melatonin is secreted appropriately at night, making you naturally sleepy.
Try opening the curtains a bit in the morning to let in light, or go for a walk if the weather is nice.
4-3. Avoid strong light at night
The third is to avoid strong light at night.
Do you spend time in a brightly lit room with lots of lights on or the TV playing right before bed?
It's known that exposure to light stops the synthesis and secretion of melatonin. Before bed, avoid strong lights and try to relax.
It's very important for you to feel like "I slept well today" when it comes to sleep. For that, create a habit that helps you relax.
Some people may find their sleep quality improves by following the three rules described above, while others may not experience much change. If you do feel a positive change, please continue with it.
Also, everyone has different ways to relax, such as listening to music or drinking warm beverages.
If you try something and feel like you "slept well" the next day, then it's important to value that feeling of yours.
Summary: Improve your sleep quality and sleep soundly
When we hear about sleep quality, we often tend to think about longer sleep durations, but we've learned that "good quality sleep" doesn't necessarily equal "long sleep duration."
At first, it may be difficult to get good quality sleep without consciously trying, but once it becomes a habit, it's not a problem.
Finally, let's summarize this article.
- Good quality sleep does not necessarily mean long sleep duration.
- For good quality sleep, 6-7 hours of sleep is ideal.
- Poor quality sleep can lead to lifestyle diseases.
- Focus on 3 rules to improve sleep quality.
If you're not getting 6-7 hours of sleep, try to increase your sleep duration even a little bit.
In addition to time, I hope you'll also work on improving the quality of your sleep. As I've said repeatedly, it's important to feel like you've had a satisfying night's sleep.
Instead of strictly adhering to what you "should" do, try to incorporate what you find beneficial and approach sleep in a way that works for you.
