Our bodies are built to sleep at night and be awake during the day. But modern life does not always cooperate. Naps, night shifts and long-haul flights all challenge the body clock. In the final part of Sleep Science, we look at how to handle them.
Napping well
A short nap can improve alertness, mood and performance, especially if you did not sleep well the night before.
- Keep it short: about 10 to 20 minutes is often recommended for a quick boost. Longer naps may lead you into deep sleep, leaving you groggy when you wake, a feeling called sleep inertia.
- Time it well: early afternoon is usually best. Napping late in the day can make it harder to fall asleep at night.
- Coffee nap: some people drink a coffee just before a short nap, as caffeine takes about 20 minutes to kick in. It is not for everyone, especially if caffeine affects your night sleep.
- Insomnia note: if you have insomnia, avoiding naps often helps build sleep pressure for the night.
Shift work
Millions of people work nights or rotating shifts in health care, transport, manufacturing and emergency services. Working against the body clock can lead to poor sleep, fatigue and long-term health risks. Some tips:
- Protect your sleep time: treat daytime sleep as seriously as night sleep, and let family and friends know your schedule.
- Make your bedroom very dark and quiet: blackout curtains, an eye mask and earplugs or white noise help.
- Manage light: bright light at the start of a night shift can help alertness; wearing sunglasses on the way home in the morning may make it easier to sleep.
- Anchor sleep: try to keep some of your sleep at the same time every day, even on days off.
- Use caffeine early in the shift, not near the end.
- Take care driving home after night shifts. If you are very sleepy, do not drive.
- Prefer forward-rotating shifts (morning to evening to night) if you have a choice, as they tend to be easier to adapt to.
Talk to a doctor if you have ongoing insomnia or severe sleepiness related to shift work.
Jet lag
Jet lag happens when you travel across time zones faster than your body clock can adjust. Symptoms include tiredness, trouble sleeping, poor concentration and stomach upsets. The body clock adjusts at roughly one time zone per day, and travelling east is often harder than travelling west.
Before you travel
- For big time changes, shift your sleep and meal times by an hour a day for a few days before you leave, in the direction of your destination.
- Arrive well rested.
On the flight
- Set your watch to destination time and try to sleep or stay awake accordingly.
- Drink water and limit alcohol and caffeine.
After you arrive
- Use light: after flying east, seek morning light at your destination; after flying west, seek afternoon and evening light.
- Eat meals at local times.
- If you must nap, keep it short.
- Some people use melatonin for jet lag; check with a doctor or pharmacist first (see Part 5).
What the whole series teaches
- Sleep is active and essential, moving through stages that support body and brain (Part 1).
- Most adults need at least seven hours, and children and teens need more (Part 2).
- Regular habits and a good bedroom are the foundation (Part 3).
- Caffeine, alcohol and food timing matter (Part 4).
- Light is your body clock's main signal (Part 5).
- Persistent insomnia is treatable, especially with CBT-I (Part 6).
- Loud snoring with gasping deserves medical attention (Part 7).
Thank you for following Sleep Science. Sweet dreams.
Sleep Science: the full series
- Part 1: How Sleep Works
- Part 2: How Much Sleep You Need
- Part 3: Better Sleep Habits
- Part 4: Caffeine, Alcohol and Food
- Part 5: Screens, Light and Melatonin
- Part 6: Insomnia
- Part 7: Snoring and Sleep Apnoea
- Part 8: Naps, Shift Work and Jet Lag (you are here)
This article is for general information only and is not medical advice. If you have ongoing sleep problems, loud snoring, breathing pauses or daytime sleepiness, please speak to a doctor.
