Know more about"Five tips for maintaining good sleep habits while staying at home and avoiding outings”

1. Purpose of creating this brochure
With the outbreak of the novel coronavirus infectious disease (COVID-19), local governments
are requesting that people refrain from going out and they are taking measures to temporarily closeschools in Japan. Under these circumstances, increased stress and time spent at home can easily
disrupt sleep habits, causing problems such as insomnia and disrupted sleep-wake rhythms.
Many studies have reported that ensuring good sleep contributes to maintaining andimproving mental and physical health. Numerous studies have also reported that sleep problems
have a negative effect on mental and physical health. Under these circumstances, the Edogawa
University Sleep Research Institute thought that it would be helpful to provide handy informationon the maintenance of good sleep habits based on scientific evidence.
2. Intention of creating this brochureThis brochure is intended for people who are suddenly compelled to change their lifestyles
and stay at home with the outbreak of COVID-19 and to help them deal with insomnia and sleepwake rhythm disturbances that are likely to occur in such situations. In addition, this brochureconsists of content that is applicable to all ages, from children to the elderly, and is easy toincorporate in their daily life.
Note that this brochure does not intend to explain how to treat clinically significant sleep
problems or sleep disorders that are not associated with lifestyle changes. It is only intended toprevent sleep problems associated with lifestyle changes and to provide advice that can preventthe problems from exacerbating. If you still have sleep problems, after following the advice here,
we recommend that you consult a medical institution specialized in sleep medicine.
3. Using this brochure
Please download and print freely, regardless of the purpose, such as by posting this at places
where people gather or notifying people you know about its contents. However, please do not
modify the content.
If you can present this brochure on some websites, please do not upload the PDF file itself;show the link to the site “Five tips for maintaining good sleep habits while staying at home andavoiding outings” in the website of Edogawa University Sleep Research Institute, described below.
Edogawa University Sleep Research Institute:“Five tips for maintaining good sleep habits while staying at home and avoiding outings”
URL： https://www.edogawa-u.ac.jp/facility/sleep/sleeptips.html

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4. Explanation of the contents of the five tips
(1) Preamble
If you spend more time at home, such as working at home or taking leave from school, you
may be more likely to have sleep problems. For example, according to a study by the Eurofound &the International Labour Office (2017), people who work using information and communication
technology in places other than offices, such as homes, experience insomnia more than those whowork in offices; insomnia has been reported to be associated with severer stress1. In addition, a
study comparing the sleep habits of children on school days to those during long-term vacation
revealed that they showed a longer sleep length, delayed sleep-wake cycle, longer sleep latency,
and more frequent sleep interruption during long vacations2.
There are various studies on the relationship between insomnia, a disturbed sleep-wakecycle, and health (e.g., Harvard Mental Health Letter, 2009)3.
(2) Tip 1: Wake-up as usual and open a curtain
It is important to wake up at the same time as a normal weekday to avoid disturbing thesleep-wake cycle. Sleep is controlled by homeostasis and circadian rhythm4. Homeostasis is amechanism through which sleep restores the brain functions. The circadian rhythm mechanism
also plays a role by causing the sleep-and-wake cycle through a biological clock in the brain. These
two mechanisms work together to control our sleep-and-wake cycle.
If wake time is delayed, sleepiness, which is caused by the homeostasis mechanism, isreduced, and the circadian rhythm mechanism is also disturbed as well. Therefore, it is importantto get up at the same time in the morning. Also, as the time spent at home increases, the internal
clock in the brain becomes more disturbed. The period of the circadian clock in the brain is notprecisely 24 hours. The clock is adjusted in synchronization with various cycles of the outside
world. Specifically, light is considered to be the most powerful synchronizer (a time cue to thebiological clock). When we are exposed to light early in the morning, our biological clock advances(earlier sleep). Conversely, when we are exposed to light in the evening and night, our biologicalclocks are delayed easily (later sleep) 5. Waking up as usual in the morning and taking in sunlightwill help you to sleep better at night.
(3) Tip 2: Avoid taking a long nap
Short naps can help improve daytime sleepiness and improve your work efficiency if you are
sleepy during daytime6. However, you should never take long daytime naps. Taking a long daytime
nap will not only have adverse effects on nighttime sleep by disrupting sleep-wake rhythms, but it
will also make you even more drowsy after waking up from the nap. The optimal time of a short nap
depends on your age and several conditions, but if you are young, it may be about 10 to 15 minutes,
and if you are an elderly person, it may be a little longer, about 20 minutes6.

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(4) Tip 3: Use your bed only when you sleep at night
You may work at a desk and sleep on the bed in the same room. In such cases, you may doyour work or study lying on your bed. It is thought that if you continue to work or study on the bed,
your brain would recognize and memorize that "the bed = a place to wake up / place to work"
based on the theory of the classical conditioning mechanism7. Once such conditioning isestablished, lying on the bed will increase your arousal level. In order for your brain to recognize
and memorize that "the bed = a place to sleep and a place to spend time calmly", use the bed only
when you sleep at night, and if you can't fall asleep, get out of bed and spend time calmly until you
feel sleepy.
(5) Tip 4: Clearly separate daytime and nighttime life
The circadian clock in the brain adjusts its time to various time cues of the outside world.
Staying home for a certain period of days makes your biological clock delayed and disturbed
because you tend to be away from the daily light cycle of the sun, such as bright at daytime anddark at night. Disturbed body clocks make it difficult to sleep at night and to get up in the morning.
For this reason, it is important for the person staying home to take in sunlight and spend active
time during daytime and to have quiet time in the evening apart from strong artificial light and yourlaptops or smartphones. Light acts as a time cue through your visual system. You should spend
your time in a sunny place during daytime. However, be aware that looking directly at the sun isdangerous to your eyes. In addition, it has been pointed out that the artificial night light delays yourbiological clock and suppresses the secretion of the biological rhythm related hormone (melatonin).
These effects are known to be stronger in children8. After the evening, darken the room and spend
time relaxing.
(6) Tip 5: Don't worry if you can't sleep well for a couple of days
Insomnia symptoms caused by stress are a normal mental and physical response. Even in theabsence of major changes in life, insomnia itself is relatively common. One out of two or threepeople is reported to "have experienced insomnia symptoms in the past month"9. When you
experience insomnia, you may "make strong efforts to fall asleep", these efforts result in you lying
fully awake in the bed or going to bed early in the night even if you are not feeling sleepy whichmakes your brain recognize and memorize "the bed = place to wake up / place to work". If you are
too concerned about insomnia symptoms, insomnia may become chronic. Please think, "Sometimes
you can't sleep because your life has changed, and it's natural," so, the next day, get up as usual in
the morning and don't take a long nap. If you stay awake during daytime the next day, "earlier" and"stronger" sleepiness would occur the next night and make it easier to sleep.

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Authors & Colleagues
Created by Edogawa University Sleep Research Institution, Chiba, Japan
Authors: Kazuhiko Fukuda, Shoichi Asaoka, & Ryuichiro Yamamoto
Colleagues: Ritsuko Nishimura & Kenta Nozoe
References
1Eurofound & the International Labour Office (2017). Working anytime, anywhere: The effects on
the world of work. Publications Office of the European Union, Luxembourg, and theInternational Labour Office, Geneva.
http://eurofound.link/ef1658（Accessed on April 8, 2020）

2

Bei B, Allen NB, Nicholas CL, Dudgeon P, Murray G, & Trinder J. (2014). Actigraphy-assessed
sleep during school and vacation periods: a naturalistic study of restricted and extended sleep
opportunities in adolescents. Journal of Sleep Research, 23(1), 107-117.

3Harvard Mental Health Letter (2009). Sleep and mental health: Sleep deprivation can affect yourmental health. Harvard Health Publishing, Harvard Medical School.
https://www.health.harvard.edu/newsletter_article/sleep-and-mental-health（Accessed on April 8, 2020）

4

Borbély AA. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195-204.

5

Minors DS, Waterhouse JM, & Wirz-Justice A. (1991). A human phase-response curve to light.

Neuroscience Letters, 133(1), 36-40.
6Hayashi, M & Hori, T. (2007) A short nap as a countermeasure against afternoon sleepiness.

Japanese Journal of Physiological Psychology and Psychophysiology, 25 (1), 45-59.
(in Japanese with English abstract)
7

Hauri P & Fisher J. (1986). Persistent psychophysiologic (learned) insomnia. Sleep, 9(1), 38-53.

8Higuchi S, Nagafuchi Y, Lee S, Harada T. (2014). Influence of light at night on melatonin
suppression in children. Journal of Clinical Endocrinology & Metabolism, 99(9), 3298-3303.

9Ohayon MM (2002). Epidemiology of insomnia: what we know and what we still need to learn.

Sleep Medicine Reviews, 6(2), 97-111.

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