Jet lag isn't just tiredness—it's your body's internal clock fighting external reality. Understanding the science helps you beat it faster.
What Is Jet Lag?
Your circadian rhythm is a roughly 24-hour internal cycle controlling when you feel alert and sleepy. It's set by:
- Light exposure (the primary driver)
- Meal timing
- Activity levels
- Social interactions
When you cross time zones rapidly, your internal clock no longer matches local time. Your body thinks it's midnight while the sun blazes outside.
Why Direction Matters
Traveling east (losing hours) is harder than traveling west (gaining hours).
Why? Your body's natural cycle is slightly longer than 24 hours. Staying awake longer (westward) aligns with this tendency. Falling asleep earlier (eastward) fights it.
Rule of thumb: Expect one day of adjustment per time zone crossed eastward, slightly less going west.
Before You Fly
Shift Your Schedule
Starting 3-4 days before departure:
- Flying east: Go to bed 1-2 hours earlier each night
- Flying west: Stay up 1-2 hours later each night
This pre-adjustment makes the transition less jarring.
Sleep Well Before Travel
Don't start sleep-deprived. Get your normal rest the nights before long flights.
Choose Flights Strategically
- Overnight eastward flights let you sleep and arrive in morning
- Daytime westward flights keep you awake, arriving tired for local bedtime
During the Flight
Reset Your Watch
As soon as you board, change your watch to destination time. Start living on that schedule mentally.
Hydrate Aggressively
Cabin air is extremely dry. Dehydration worsens jet lag symptoms. Drink water constantly, and limit alcohol and caffeine.
Sleep Strategically
If it's nighttime at your destination: Sleep on the plane. Use eye masks, earplugs, and neck pillows. Consider mild sleep aids (but test them before travel).
If it's daytime at your destination: Stay awake. Watch movies, read, walk the aisles.
Move Around
Blood circulation helps everything. Walk the aisles hourly if possible.
Eat Lightly
Heavy meals are harder to digest. Eat smaller portions and choose lighter options.
First Day at Destination
This is the crucial day. Get it right, and recovery accelerates.
Prioritize Light Exposure
Light is the most powerful tool for resetting your clock.
Eastward travel (need to advance clock):
- Get bright morning light
- Avoid evening light
Westward travel (need to delay clock):
- Avoid morning light
- Get bright afternoon/evening light
Sunlight is ideal. If overcast, bright indoor light or light therapy boxes help.
Stay Awake Until Local Bedtime
This is the hardest part. Your body screams for sleep. Resist.
Strategies:
- Stay outside (light and activity)
- Exercise in the afternoon (not evening)
- Avoid heavy meals that induce drowsiness
- Take a brief power nap (20-30 minutes max) if desperate, but set an alarm
- Stay socially engaged
Eat on Local Schedule
Meals help set your clock. Eat breakfast, lunch, and dinner at normal local times, even if not hungry.
Supplements and Medications
Melatonin
The most studied jet lag supplement:
- Eastward: Take 0.5-3mg at local bedtime
- Westward: Generally less effective; avoid or take upon waking if needed
Start the first night at destination and continue 4-5 days. Lower doses often work as well as higher ones.
Caffeine
Strategic caffeine helps:
- Use it to stay awake when needed
- Avoid within 6 hours of desired bedtime
- Don't overdo it—jitters add to disorientation
Sleep Aids
Prescription or over-the-counter sleep aids can help on flights or the first nights. But:
- Test before travel (reactions vary)
- Use minimally
- They don't address circadian adjustment
Avoid Alcohol
Alcohol disrupts sleep quality, dehydrates you, and worsens jet lag despite initial drowsiness.
Technology Tools
Apps
Timeshifter: The most science-backed jet lag app. Creates custom plans based on your flight schedule, sleep patterns, and destination.
Jet Lag Rooster: Free alternative with light exposure recommendations.
Light Therapy Glasses
Products like Luminette or Re-Timer provide bright light exposure on demand. Useful when sunlight isn't available.
Specific Scenario Tips
Short Trips (3-4 Days)
For very short trips, staying on home time might be easier than adjusting. Schedule meetings and activities for hours that align with your home schedule.
Multiple Time Zone Stopovers
If you have a long layover, use it for sleep or light exposure based on your final destination.
Long-Haul East Then West (or Vice Versa)
On round-the-world itineraries, the direction issue compounds. Adjust where possible, but accept some fatigue.
Arriving for Important Events
If you have critical meetings or events:
- Arrive 2-3 days early if possible
- Pre-adjust more aggressively before departure
- Schedule key events for times you'd naturally be alert
Exercise and Movement
Physical activity helps reset circadian rhythms and reduces fatigue.
Best approach:
- Light exercise on arrival (walking exploration is perfect)
- More intense exercise in afternoon
- Avoid vigorous exercise near bedtime
Recovery Timeline
Days 1-2: Worst symptoms. Focus on light exposure and staying on local schedule.
Days 3-4: Significant improvement. Sleep should normalize.
Days 5-7: Most people fully adjusted.
Factors that slow recovery:
- More time zones crossed
- Eastward direction
- Older age
- Staying indoors
- Irregular eating/sleeping
Common Mistakes
Napping Too Long
Brief naps (20-30 min) can help. Longer naps set back adjustment by giving your body the "wrong" sleep signal.
Using Screens at Night
Bright screens emit blue light that signals "daytime" to your brain. Avoid for 1-2 hours before bed, or use blue-light filters.
Giving Up on Day One
The first day is brutal. It gets better. Push through rather than surrendering to inappropriate sleep.
Relying Only on Sleep Aids
Pills don't reset your circadian clock—they just help you sleep despite it. Use them as supplements to behavioral strategies, not replacements.
The Mindset Shift
Some jet lag is inevitable. Accept mild symptoms rather than expecting perfection. Your body is doing remarkable adaptation work.
Frame the experience positively: You traveled across the planet. That's extraordinary. A few days of adjustment is a small price for exploring the world.
Quick Reference
| Direction | Pre-Flight | During | First Day | Melatonin | |-----------|------------|--------|-----------|-----------| | Eastward | Sleep earlier | Sleep on plane | Morning light | At local bedtime | | Westward | Sleep later | Stay awake | Afternoon/evening light | Generally skip |
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