Prevention
Prevention
Your inner clock keeps steadier time when day and night feel different: mornings are bright and active, evenings quiet and dim, and you get up at roughly the same time. None of the habits described here treats illness or replaces a doctor. But together they give your rhythm clear reference points and often make everyday life easier.
Your inner clock loves predictability. The same morning repeated many times tells it more than any feat of willpower.
What you'll need
- A few days of observation: when you actually fall asleep, wake up and feel most alert
- A wake-up time you can realistically keep on both weekdays and weekends
- A chance to get outside, even briefly, during daylight hours
- A bedroom you can darken at night
- Willingness to see a doctor if your sleep and daytime alertness don't improve
Get up at the same time every day
A consistent wake-up time is the main anchor of your routine. Your bedtime will follow it, as long as you don't sleep in for long stretches in the morning, weekends included.
Example: the alarm goes off at the same hour all week, and on Saturday the person allows themselves only a little extra time in bed.
Catch light in the morning and during the day
Light is the main external cue for your inner clock. A morning walk, breakfast by the window or working in a bright room helps your rhythm recognize that the day has started.
Example: the person walks part of the way to work instead of riding all the way to the door.
Stay active through the week
According to the 2020 WHO guidelines, adults need 150–300 minutes of moderate aerobic activity a week, or 75–150 minutes of vigorous activity. Moving during the day, especially outdoors, pairs well with daylight.
Example: the lunch break turns into a brisk walk around the block.
Dim the evening
As bedtime approaches, soft, warm light and calm activities signal to the body that night is near. Bright overhead light right up until bedtime sends the opposite signal.
Example: after dinner only a desk lamp is on in the room, and the ceiling light is off.
Put bright screens away before bed
Phones, tablets and TVs don't just give off light — they also draw you in, pushing sleep further back. It's better to set them aside well before bed and do something unhurried.
Example: the phone charges in the kitchen, and a paper book takes its place in the bedroom.
No coffee or heavy meals late at night
Strong tea and coffee are best enjoyed in the first half of the day. A large late dinner can also make it harder to fall asleep, so try not to leave your main meal for the night.
Example: in the evening the person makes a caffeine-free herbal tea and has dinner earlier.
Leave enough time for sleep
The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults sleep 7 hours or more for good health, and do so regularly. If your alarm goes off early, plan your bedtime accordingly.
Example: the person counts back from the alarm to set a bedtime and adds an evening reminder.
Don't put off seeing a doctor
If your sleep hasn't improved for weeks, you struggle with daytime sleepiness or low mood won't lift, make an appointment with your primary care doctor. They will assess your overall health and refer you to another specialist if needed.
Example: the person brings a sleep diary from the past few weeks and a list of their questions to the appointment.
Common mistakes
- Trying to rebuild your routine overnight by moving the alarm abruptly
- Sleeping until noon on weekends and then wondering why Monday is so hard
- Spending the whole day in a dim room and switching on the brightest lights in the evening
- Falling asleep phone in hand, scrolling an endless feed
- Fighting daytime sleepiness with coffee alone without changing your routine
- Choosing sleep aids for yourself without talking to a doctor
If it doesn't work
- If you have no time for a morning walk, drink your tea by the brightest window and open the curtains as soon as you get up
- If it's been overcast for a long time, go outside during the day anyway: even a cloudy day is brighter than a room
- If you have to work at a screen in the evening, turn down the brightness and take a break before bed
- If your schedule doesn't let you get up at the same time, keep at least a steady routine on your days off and consult a doctor
- If you stick to your routine but still lack energy, discuss it with your primary care doctor — the cause may not be your habits
Check yourself
- You get up at about the same time on weekdays and weekends
- You spend time in the light in the first hours after waking
- Your week includes physical activity that suits you
- In the evening the lighting at home is softer and dimmer than during the day
- Screens are put away before you go to bed
- Coffee stays in the first half of the day
- You leave 7 hours or more for sleep
- You know when it's time to see a doctor
Situation — what you may notice — what to try
| Situation | What you may notice | What to try |
|---|---|---|
| A teen falls asleep later and later | They're hard to wake in the morning and sluggish during the day | Agree on a fixed wake-up time, morning light and evenings without screens in bed |
| An older adult wakes up too early | They get sleepy in the evening well before their usual time | Spend more time in daylight and discuss the routine with a doctor |
| Winter and short days | Mornings are dark, getting up is hard, energy is lower | Go outside during daylight hours and keep a fixed wake-up time |
| Working late into the evening | Thoughts and the screen won't let go, sleep keeps getting pushed back | Set a time after which you don't open anything work-related |
| Low mood persists despite a good routine | Nothing feels enjoyable, everyday tasks are a struggle | Don't wait for spring — see a doctor |
Read next
- Topics
A map of topics: how the inner clock works, light through the day, chronotype, shift schedules, long flights, northern latitudes, plus the catalogue.
- Approaches
How to plan sleep and light around shift work, after a flight and above the Arctic Circle, who to see and how to keep a sleep diary.
- Ask your doctor
Questions about sleep, shift schedules, daytime sleepiness and supplements that are worth raising with your own doctor.
- Glossary
Body rhythm terms in plain language: from circadian rhythm and chronotype to the sleep diary and polar day.
Sources
- American Academy of Sleep Medicine — recommendations on adult sleep duration (2015)
- WHO — guidelines on physical activity and sedentary behavior (2020)
This guide draws on the Nobel Committee's announcement of the 2017 prize, the recommendations on adult sleep duration and the WHO guidelines on physical activity as they were available when the texts were written. Scientific understanding of sleep rhythms keeps evolving, so questions about your own health are best discussed with a doctor.