Sleep debt, what is it?

First, please refer to the following list:

If you experience any of the above, you might already have sleep debt.

Accumulated sleep debt can lead to physical and mental health issues.

This time, gugu sleep will explain sleep debt.

Let's learn about sleep debt and pay it off (resolve it)!

What exactly is "sleep debt"?

What exactly is "sleep debt"?

Sleep debt refers to the difference between the amount of sleep your body needs and the amount of sleep you actually get.

For example, if person A's body needs 8 hours of sleep, but they only get 6 hours, person A has accumulated 2 hours of sleep debt.

While 2 hours of sleep debt might seem minor, it adds up to 20 hours in 10 days and 730 hours in a year.

Small daily sleep debts can accumulate and unknowingly cause various health problems, so it's important to avoid even small amounts of sleep debt.

Perhaps some of you might be thinking, "I'm fine because I don't feel particularly sleepy or tired."

However, research has shown that even if sleep debt has accumulated, you don't necessarily feel sleepy or tired.

Even if you don't feel sleepy or tired, sleep debt might be accumulating without your knowledge, and that sleep debt could be causing physical and mental health problems.

Reference:National Library of Medicine (NIH)

Did you know that many Japanese people might actually be experiencing sleep debt?

According to a 2019 survey by the Ministry of Health, Labour and Welfare, approximately 40% of Japanese people sleep 6 hours or less per day on average.

While the amount of sleep needed per day varies by age and individual, considering that the average is 6 to 8 hours, this means 1 in 3 Japanese people are experiencing sleep debt.

Reference:Ministry of Health, Labour and Welfare "National Health and Nutrition Survey"

Impact of sleep debt on physical and mental health

What kind of impact does accumulated sleep debt have on physical and mental health?

From here, we will look at the physical and mental problems

that can arise due to sleep debt.

Physical health issues that may arise due to sleep debt include the following:

When sleep debt accumulates, the autonomic nervous system and hormone balance become disrupted, which can worsen and make it easier to develop lifestyle-related diseases such as high blood pressure and diabetes.

Additionally, when sleep debt accumulates, leptin, a hormone that suppresses appetite, decreases, while ghrelin, a hormone that stimulates appetite and hunger, increases, making it easier to gain weight.

Reference:National Library of Medicine (NIH)

Mental health issues that may arise due to sleep debt include the following:

As sleep debt accumulates, substances such as serotonin become depleted within the body, leading to decreased concentration and judgment, as well as an increased likelihood of unstable emotions such as depressive states, anxiety, and irritability.

As a result, there is a risk of falling into a vicious cycle of "decreased work efficiency/performance → sacrificing sleep to get work done → increasing sleep debt."

How to check for sleep debt

While an accurate check for sleep debt should be done at a hospital, you can easily check it yourself by applying your sleep duration to the following formula:

If the result of the equation is positive instead of negative, you may have accumulated sleep debt.

How to repay (resolve) sleep debt

So, how can you resolve sleep debt?

Unfortunately, there is only one way to resolve sleep debt: get enough sleep every day, as much as your body needs.

Here are some tips to help you get enough sleep.

If you can repay (resolve) your sleep debt, you can expect to be less susceptible to things like colds, and enjoy mental stability, as well as improved judgment and concentration, leading to overall physical and mental health. Even if it's little by little, let's work to resolve sleep debt.

By creating a routine before bed, you can naturally ease into sleep and get enough sleep every day.

Think about your own actions before bed. Are you using your smartphone or playing games before going to sleep?

A 2019 survey showed that nearly half of people in their 20s cited smartphones and games as factors hindering them from getting enough sleep.

The blue light emitted from smartphones and games has been confirmed to induce a state of wakefulness, which can interfere with getting enough sleep daily.

We recommend creating a routine that helps your body relax, such as putting away your smartphone, TV, and games about 30 minutes before bed and having a warm drink, to naturally ease into sleep.

Keeping a sleep diary can help you understand your sleep patterns and the behaviors that affect your daily sleep, which can be useful in identifying what's preventing you from getting enough sleep each day.

If you're unsure what to write in your sleep diary, we recommend noting the following:

Once you know the cause, you can address it, which will help you get enough sleep every day.

To ensure you get enough sleep every day, it's also important to make your bedroom an optimal environment for sleeping.

Check the following points to see if your bedroom is optimized for sleep:

If you want to know the optimal humidity for sleep, please refer to this article: "Surprisingly Unknown: The Optimal Humidity for Sleep in Your Bedroom!"

While the effect of taking a nap on resolving sleep debt is limited, napping can refresh both mind and body, and boost concentration that may have declined due to sleep debt.

Also, it's recommended to take naps between 12 PM and 3 PM. Napping after 3 PM may affect your nighttime sleep, so try to avoid it if possible.

Can you resolve sleep debt by sleeping in on weekends?

Many people probably think that "if it's a sleep problem, I can fix it by sleeping in."

Unfortunately, it is still unclear whether sleeping in on days off can resolve sleep debt.

Sleeping in on days off is actually not recommended, as it can disrupt your daily routine and sleep rhythm.

If your sleep debt has accumulated to a level that interferes with your daily life, it is recommended to consult a doctor.

Let's re-evaluate how you approach sleep, starting with sleep debt

How do you perceive sleep?

Sleep is extremely important as preventive medicine; getting adequate sleep helps prevent illness and builds a healthy body.

Even if you lead a busy life and find it difficult to get enough sleep, try to implement the advice we've shared today and gradually resolve your sleep debt.

To avoid accumulating sleep debt, be sure to get enough sleep every day and live a healthy life!

Better sleep, better you.
better sleep better you