Sleep Better

Lesson 12: Naps, shift work and jet lag

Goal: nap without wrecking your night, and protect your sleep when work or travel puts your body clock out of step.

Naps

A short nap can be a real performance boost. In a famous 1995 NASA study, long-haul pilots given a 40-minute rest opportunity in the cockpit (they slept for about 26 minutes on average) showed 34% better performance and 54% better alertness than pilots who didn’t rest.

• Keep it short: 10 to 20 minutes. That’s long enough to refresh you but short enough to avoid deep sleep, so you don’t wake groggy. Set an alarm.
• Nap early: before about 3 pm, or at least 7 to 8 hours before bedtime, so you don’t use up the sleep pressure you need at night.
• If you have insomnia, skip naps while you’re working on it (Lesson 10).
• If you feel you need a nap every day, look at your night-time sleep first (Lesson 3).

Shift work

Working nights or rotating shifts puts you awake when your body clock says sleep, and asleep when it says wake. You can’t fully fix that, but you can make it much better.

Protect your day sleep:

• Make the bedroom truly dark (blackout blinds or foil plus an eye mask), cool and quiet (earplugs, white noise).
• Tell family and friends your sleep hours. Turn the phone and doorbell off.
• Try to sleep at the same time after each night shift, ideally soon after getting home.

Use light deliberately:

• Get bright light during the first part of your shift to stay alert.
• Treat the end of your shift as your sunset. Keep light low on the way home: wear sunglasses on the commute, even on a grey morning, and keep the house dim before bed. Bright morning sun on the drive home tells your body clock it’s morning, which is the opposite of what you want before day sleep.
• When you wake for your next shift, that’s your “morning”: get bright light (outdoors if it’s still light) to anchor the new day.

Stay safe:

• A 20-minute nap before a night shift can improve alertness.
• Use caffeine early in the shift, not in the last few hours.
• Drowsy driving after a night shift is dangerous. Remember that 17 hours awake is comparable to a blood alcohol level of 0.05% (Lesson 1). If you’re struggling to keep your eyes open, nap first, take public transport or get a lift.

Jet lag

Your body clock shifts by only about an hour a day on its own, so without help jet lag lasts roughly one day per time zone travelling west and about one and a half days per time zone travelling east. East is harder for most people because the body clock naturally runs a little longer than 24 hours, so it’s easier to stay up later (going west) than to sleep earlier (going east).

Light timing is the most powerful tool:

• Flying east (for example, Perth to Sydney, or Australia to the Americas across the date line): seek morning light and avoid bright light in the evening at your destination.
• Flying west (for example, Australia to Europe): seek evening light and avoid very early morning light for the first few days.
• Switch your meals and sleep to destination time as soon as you can.
• Get outside in daylight at the right times on arrival; it beats any gadget.

Apps such as Timeshifter calculate personalised light schedules for a trip. Melatonin can help with jet lag for some people, but in Australia it’s prescription-only for most adults, so ask your doctor or pharmacist (Lesson 13).

Exercise 12

If you nap, set an alarm for 20 minutes next time and note how you feel afterwards. If you work shifts, write down your “sunset” routine for the trip home and try it after your next night shift.

Sources

• Sleep Foundation, Napping: benefits and tips and The NASA nap
• Sleep Health Foundation, Shift work
• Williamson & Feyer (2000), Moderate sleep deprivation and alcohol intoxication, Occupational and Environmental Medicine
• Sleep Foundation, How to get over jet lag
• Timeshifter, Is jet lag worse going east or west?

This course is general information, not medical advice. If you have ongoing sleep problems, loud snoring with pauses or gasping, or sleepiness that affects driving or work, see your doctor. In Australia, if you are struggling or feel unsafe, call Lifeline on 13 11 14.