Stanford sleep physician Dr. Cheri D. Mah reveals how to trick your body clock
Simple schedule tweaks before you even board can erase days of sluggishness
Shocking 'First Night Effect' means half your brain stays awake in hotel rooms
The essential £5 packing hacks to ensure you get the perfect night's sleep
By TRAVEL TODAY REPORTER
PUBLISHED: 11:43 BST, 21 October 2025 | UPDATED: 12:05 BST, 21 October 2025
We’ve all been there. You spend months planning the ultimate getaway—booking the finest restaurants, mapping out the perfect sightseeing tours, and packing your best outfits.
But there is one critical thing millions of holidaymakers completely forget to plan for: how to actually get a decent night’s sleep.
Now, a top sleep expert from Stanford University has revealed that simply jumping on a plane and hoping for the best is a recipe for disaster. Instead, she claims a few incredibly simple, proactive biological hacks can completely cure the dreaded holiday jet lag before you even touch down.
The Secret Strategy BEFORE You Fly
According to Dr. Cheri D. Mah, co-head of the Restorative Sleep pillar at Stanford Lifestyle Medicine, our internal body clocks take roughly one full day to adjust for every single time zone we cross.
That means a flight from California to New York could leave you feeling like a zombie for the first three days of your hard-earned break.
The cure? You need to start manipulating your body clock days before you leave.
"Most people just jump on an airplane and then try to adjust their body clock after they arrive, which is not really a plan," warns Dr. Mah. "Instead, we can be more proactive."
How to shift your clock:
Heading East? (e.g., London to Dubai or LA to New York): Go to bed an hour earlier and wake up an hour earlier every day for a few days before your trip.
Heading West? Do the exact opposite—push your bedtime and wake-up time an hour later.
The Golden Rule: Never start a trip already sleep-deprived. Ensure you log plenty of hours in bed for several nights leading up to your flight.
The In-Flight Mistake Millions of Us Are Making
It is the ultimate pre-holiday ritual for many: boarding the aircraft, accepting a glass of complimentary wine, and binge-watching Hollywood blockbusters until landing.
But experts say this is the worst thing you can possibly do.
To defeat jet lag, you must force your body into the destination's time zone the second you step onto the aircraft. This means meticulously planning when you eat and sleep mid-air.
Dr. Mah advises travellers to completely shun alcohol, caffeine, and sugary beverages, which wreak havoc on sleep quality. Holidaymakers should also avoid high-action or horror movies that overstimulate the brain, opting instead for a book or relaxing music.
Because airlines notoriously serve meals at awkward times, Dr. Mah says it is vital to bring your own snacks so you can eat according to your destination's schedule, even if the cabin lights are switched off.
The Terrifying Reason You Can't Sleep in Your Hotel Room
Have you ever noticed that the first night in a luxury hotel room leaves you feeling tossing, turning, and completely exhausted?
There is a sinister biological reason for it.
Incredible scientific research has revealed the "First Night Effect"—a evolutionary survival mechanism where the left side of your brain actively stays more alert to monitor an unfamiliar environment for danger. Essentially, half your brain is staying awake to keep you safe!
To override this primitive response, Dr. Mah suggests a brilliant psychological trick: brand loyalty. By staying at the same hotel chain, your nervous system recognises the familiar layout and relaxes.
If that isn't possible, you must trick your brain by bringing the scents and textures of home with you. Spritzing your pillow with a familiar lavender spray, bringing your own pillowcase, or placing a photo of a loved one on the hotel bedside table can instantly signal to your brain that you are safe, allowing you to drop into a deep, restorative sleep.
How to Recover Fast After Landing
If you are still feeling the effects of a long-haul flight after landing eastward, the Stanford expert recommends a strict regime of morning sunlight and morning caffeine, while strictly avoiding bright light in the evening.
If you hit a wall in the afternoon, a 20-to-30-minute power nap or a quick burst of exercise can reboot your system—just ensure any caffeine is consumed at least 10 hours before your new bedtime.
Dr. Mah also notes that over-the-counter melatonin can be highly effective when shifting body clocks eastward, but warns travellers to buy trusted brands, as many labels do not accurately represent what is inside the bottle.
The Ultimate Ultimate 'Sleep Kit' Packing List
Before you jet off on your next adventure, ensure your hand luggage contains these essential items to guarantee perfect sleep:
Item | Why you need it |
Eye Mask & Earplugs | Crucial for blocking out cabin light and noisy passengers. |
Home Pillowcase | Instantly tricks the brain into feeling safe and secure. |
Curtain Clips | Stops annoying gaps in hotel curtains from letting in early morning sun. |
Light-blocking Stickers | To cover up glowing standby lights on hotel TVs and appliances. |
Journal & Pen | Writing a quick to-do list before bed effectively empties your mind of travel anxiety. |
"Sleep tools and technologies continue to improve," Dr. Mah concludes, teasing that adaptive white noise machines and temperature-controlled travel mats are the future of holiday rest.
But until then, a few clever tweaks to your routine might just be the ultimate cure holidaymakers have been praying for.