- Jet lag is a term for the difficulties associated with travelling across time zones.
- Travelling eastwards tends to be more challenging in this regard.
- Fortunately, there are simple tricks to mitigate the effects of jet lag.
What is jet lag?
Jet lag is a collective term for the difficulties associated with travelling across time zones. The most common symptoms include fatigue, drowsiness, insomnia, and in some cases, digestive issues.
While jet lag is not dangerous, it can significantly disrupt your travel experience. So, what causes jet lag, and how can you reduce its impact?
Jet lag: an earthquake for your circadian rhythm
The human body has its own internal clock, located in the brain. While it doesn’t have visible hands like the clock on your bedside table, it still runs on a 24‑hour cycle. This invisible clock forms the basis of your circadian rhythms.
Circadian rhythms help ensure alertness and productivity during the day, and signal your body to wind down at night. If you’ve ever wondered why you sometimes wake up just before your alarm goes off —circadian rhythms offer the explanation.
But when you cross several time zones, it’s like an earthquake for your internal clock. While it may be getting dark at your destination, your body still feels like it’s lunchtime. This mismatch between external time and internal time is the root cause of jet lag.
When is jet lag at its worst? East or West?
Jet lag becomes more intense the more time zones you cross. While a short hop across 1–3 time zones may go unnoticed, a flight to New York or Beijing, crossing six or more time zones, will likely leave you jet‑lagged.
The direction you travel also plays a role.
Travelling eastward is generally more disruptive than travelling west. The reason is quite simple:
- When you travel east, your body is expected to go to bed earlier than it's used to, while your internal clock is still aligned with daytime. This often results in difficulty falling asleep and subsequent sleep deprivation.
- On the other hand, travelling west means extending your day, which tends to be easier to adjust to. You might be extra tired by the evening, but falling asleep is less of a challenge than when travelling east.
5 practical tips to reduce jet lag
1. New destination, new time
Whatever time of day you arrive, try to adapt to the local routine as quickly as possible. If you arrive in the morning, resist the urge to nap—stay awake and push through until evening.
If you arrive in the evening, get some sleep and start fresh the next morning. This will help your body clock adjust and synchronise with the new time zone more quickly.
2. Reach for the melatonin
Melatonin is a natural sleep hormonereleased when you're exposed to darkness. It’s also available over the counter at pharmacies and can help you fall asleep more easily.
Jet lag is one situation where melatonin supplementation can really help with adjustment. Take a dose around 60 minutes before you plan to sleep.
3. Adapt to a new diet
Eating habits also play a role in resetting your internal clock. Following regular mealtimes according to your new time zone can help re‑establish a healthy sleep rhythm.
4. Let daylight help you
Your circadian rhythms are regulated by the hormone melatonin, which is controlled by your exposure to light. Melatonin is secreted in the evening and at night, when it's dark.
If you arrive in the evening but still feel like it’s daytime, avoid screens and bright lights—this will encourage natural melatonin production and help you fall asleep.
If you arrive in the morning but feel like crawling into bed, expose yourself to sunlight to signal your body to stay awake and help you feel more alert.
5. Plan for jet lag in advance
Jet lag typically affects people for 1–2 days after arrival. Be kind to yourself—don’t plan intense activities right away.
Avoid scheduling demanding excursions or high‑stakes events for the first couple of days. Save the most exciting parts of your trip for later, when you’ll feel more rested and ready to enjoy them.
Even professional athletes often arrive days in advance of competitions. That’s because jet lag has been shown to reduce physical performance for several days after arriving at a new destination.
Bottom line
Jet lag is caused by a temporal disruption of the natural biorhythms that regulate our circadian rhythm. The more time zones we cross, the more these rhythms are disturbed. Research also shows that travelling east tends to result in more severe symptoms than travelling west.
Jet lag usually disappears within a few days as the circadian rhythm adapts to the new time. You can support this adjustment by immediately aligning with the local time upon arrival. Taking melatonin tablets can also help promote sleep and speed up the adjustment process.
