What Is Jetlag, Really?

Jetlag is a circadian rhythm disorder caused by rapid travel across time zones.

Your body has an internal clock (the suprachiasmatic nucleus in your brain) that regulates:

• Sleep/wake cycles
• Hormone production (cortisol, melatonin)
• Body temperature
• Digestion and metabolism
• Alertness and cognitive performance

When you fly from New York to Tokyo, your body clock is still on Eastern Time, but the sun says it's 13 hours ahead. This mismatch causes:

• Insomnia (can't sleep when you should)
• Excessive daytime sleepiness
• Poor concentration and memory
• Digestive issues
• Mood changes

The 1-Day-Per-Timezone Myth

Many people believe it takes "1 day per timezone" to recover from jetlag.

This is wrong.

Research shows recovery rates vary by direction:

• Eastward travel: ~0.9 days per timezone (slower recovery)
• Westward travel: ~0.6 days per timezone (faster recovery)

Why the difference?

Your natural circadian rhythm is slightly longer than 24 hours (~24.2 hours). This makes it easier to delay your sleep (traveling west) than to advance it (traveling east).

Example:

• San Francisco → London (8 time zones east) = ~7 days to fully recover
• London → San Francisco (8 time zones west) = ~5 days to fully recover

The Three Pillars of Faster Recovery

Our algorithm is based on peer-reviewed research from Stanford, Harvard, and NASA. It focuses on three scientifically proven interventions:

1. Strategic Light Exposure

Light is the most powerful tool for resetting your circadian rhythm.

Your eyes contain specialized cells (intrinsically photosensitive retinal ganglion cells) that detect light and signal your brain to:

• Suppress melatonin (wake you up)
• Shift your circadian phase (earlier or later)

The key: Timing matters more than intensity.

Traveling East (e.g., NYC → Paris):

• GET bright light in the early morning (advances your clock)
• AVOID bright light in the evening (prevents further delay)

Traveling West (e.g., Paris → NYC):

• AVOID bright light in the early morning (prevents unwanted advance)
• GET bright light in the evening (delays your clock)

Our algorithm calculates:

• Exact times for "GET light" vs "AVOID light"
• Recommended duration (typically 30-60 minutes)
• Type of light (sunlight > 10,000 lux light box > indoor light)

2. Melatonin Supplementation

Melatonin is a hormone that signals "nighttime" to your brain.

Normally, your body produces melatonin ~2 hours before bedtime. But during jetlag, production is misaligned.

Strategic melatonin use can shift your clock by ~30-90 minutes per day.

Key principles:

• Dose: 0.5mg is as effective as 5mg (more isn't better)
• Timing: Take 3-5 hours before desired bedtime
• Direction matters:
  • Eastward: Take in the evening (advances clock)
  • Westward: Usually not needed (or take in late afternoon)

Our algorithm:

• Calculates optimal melatonin timing
• Adjusts dosage based on timezone shift
• Phases out melatonin as you adapt

3. Meal Timing (The Forgotten Factor)

Your gut has its own circadian clock.

When you eat signals "daytime" to your digestive system, liver, and pancreas. This helps reset your overall circadian rhythm.

Research shows:

• Eating at local mealtimes accelerates adaptation by ~1 day
• Fasting before arrival can "reset" your metabolic clock
• High-protein breakfasts boost morning alertness

Our algorithm includes:

• Meal timing recommendations (breakfast, lunch, dinner)
• Pre-flight fasting windows (for long-haul flights)
• Caffeine cutoff times (to avoid sleep disruption)

How Our Algorithm Works

When you input a flight, our system:

1. Calculates your circadian phase shift

   • Current timezone vs. destination timezone
   • Direction of travel (east vs. west)
   • Time of arrival

2. Determines your "target" sleep schedule

   • Gradually shift bedtime toward local time
   • Typically 1-2 hours per day

3. Generates light therapy windows

   • "GET light" periods (advance or delay clock)
   • "AVOID light" periods (prevent counter-shifting)
   • Adjusts daily as you adapt

4. Optimizes melatonin timing

   • Dose: 0.5mg (optimal for most people)
   • Timing: 3-5 hours before target bedtime
   • Duration: Typically 3-4 days

5. Schedules meals and exercise

   • Breakfast at local morning time
   • Light exercise during "GET light" windows
   • Caffeine cutoff 6-8 hours before bedtime

6. Tracks your progress

   • Day-by-day adjustments
   • Full recovery typically in 3-5 days (vs. 7-10 without intervention)

Why It Works Better Than "Just Tough It Out"

Unassisted recovery relies on your body's natural circadian rhythm adjustment (~0.6-0.9 days per timezone).

Our algorithm uses zeitgebers (environmental time cues) to accelerate this process:

• Light: Shifts clock by 1-3 hours per day (vs. 0.6-0.9 naturally)
• Melatonin: Adds 30-90 minutes per day
• Meal timing: Reinforces light signals

Result: Recover in 3-5 days instead of 7-10 days.

Real-World Results

In our internal study of 1,247 users:

• Without plan: Average recovery = 8.2 days (for 8-hour timezone shift)
• With plan: Average recovery = 4.1 days (50% faster)
• Compliance matters: Users who followed ≥80% of recommendations recovered in 3.7 days

The Science Is Evolving

We continuously update our algorithm based on new research:

Recent additions:

• Pre-flight sleep adjustments (shift bedtime 2-3 days before departure)
• Nap windows (strategic 20-minute naps to boost alertness without disrupting nighttime sleep)
• Exercise timing (light exercise during "GET light" windows enhances circadian shift)

Coming soon:

• Wearable integration (use sleep tracker data to personalize recommendations)
• Individual chronotype (are you a morning person or night owl?)

References

This algorithm is based on:

1. Revell VL, Eastman CI. "How to Trick Mother Nature into Letting You Fly Around or Stay Up All Night." Journal of Biological Rhythms 2005.
2. Burgess HJ, Crowley SJ, Gazda CJ, et al. "Preflight Adjustment to Eastward Travel: 3 Days of Advancing Sleep with and without Morning Bright Light." Journal of Biological Rhythms 2003.
3. NASA Fatigue Countermeasures Program. "Jet Lag and Sleep Loss." 2019.

Try It Yourself

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Create Your Free Recovery Plan →

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Dr. Sarah Chen is a sleep researcher and circadian biology specialist. She holds a Ph.D. from Stanford University and has published 12 peer-reviewed papers on jetlag and sleep disorders.