Cover It can be difficult to adjust your circadian rhythm after a long-haul flight, but it’s not impossible. (Photo: Freepik)
It can be difficult to adjust your circadian rhythm after a long-haul flight, but it’s not impossible. (Photo: Freepik)
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From melatonin to light cues, here’s how to reset your circadian rhythm and bounce back after a long-haul flight
Long-haul flights are often more than just inconvenient—they can wreak havoc on your internal systems, especially your sleep-wake cycle. Jet lag isn’t simply tiredness; it’s a physiological disruption to your circadian rhythm, the internal clock that governs everything from alertness to digestion. This misalignment between your body’s natural schedule and the local time zone can lead to insomnia, sluggishness and even mood disturbances. Whether you’re flying for business or leisure, recalibrating your circadian rhythm quickly and effectively is key to arriving energised and functional. Here’s how to do it, based on the latest science.
Read more: Airplane etiquette: Which beauty rituals are acceptable at 30,000 feet?
Know the enemy: circadian misalignment
Jet lag is caused by a breakdown in communication between your circadian rhythm and the external cues of your destination. As highlighted in a 2019 Frontiers in Physiology review, your internal clock doesn’t instantly adjust to a new time zone, especially after travelling across three or more. The result is physiological chaos: your body thinks it’s bedtime at lunchtime, or vice versa.
The effects are direction-dependent. Eastward travel tends to be harder than westward, as it’s harder to advance your internal clock than delay it. This is why a flight from Los Angeles to Tokyo can feel far more disorienting than the reverse.
1. Get some sun
Above Mindful light exposure is key to resetting your circadian rhythm. (Photo: Freepik)
Mindful light exposure is key to resetting your circadian rhythm. (Photo: Freepik)
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Sunlight can be your most powerful ally or your worst enemy. Light exposure can either advance or delay your circadian rhythm, depending on timing. Indiscriminate exposure may do more harm than good, especially after eastward travel. The key is precision.
After a westward long-haul flight, you’ll want to seek light in the late afternoon and evening to delay your internal clock. Conversely, after an eastward journey, early morning light exposure is crucial to advance it. But avoid bright light in the first half of the day if you’re trying to shift forward—doing so may actually reinforce your old timezone alignment.
2. Use melatonin strategically
Using melatonin is circadian signalling. Your body naturally produces it in the evening to help wind down. Supplementing melatonin can help shift your circadian rhythm in the right direction, but timing is everything. According to the same 2019 research by Roach and Sargent, a 3 mg dose of melatonin taken 11.5 hours before your body’s natural low point in core temperature (usually around 4am) can help advance the rhythm—ideal for eastward flights. Conversely, to delay the rhythm after a westward flight, melatonin is most effective four hours after that low point. Use it wisely: taken at the wrong time, it can push your clock in the wrong direction.
3. Time your exercise (or don’t)
Moderate exercise may also help shift your circadian rhythm, but its effects are less predictable than those of light or melatonin. If used, the general rule is: exercise in the morning for phase advances, evening for phase delays. That said, unlike melatonin and light, exercise doesn’t seem to have additive effects and isn’t essential to the process.
4. Consider pre-flight preparation
For frequent travellers or those with high-stakes schedules—athletes, performers, executives—starting the adjustment before takeoff can be worth the effort. This involves shifting your sleep schedule gradually over a few days, using light exposure and melatonin to pre-adapt to the destination time zone. However, as the Sleep Foundation notes, this strategy isn’t always practical due to work and social obligations. So the best you can do is try to stay healthy through movement and hydration, to mitigate fatigue or sluggishness from travelling.
5. Don’t confuse travel fatigue with jet lag
Not all post-flight tiredness is circadian in nature. Travel fatigue—caused by dehydration, poor sleep and extended cabin time—is a separate issue. Unlike jet lag, it usually resolves with one good night’s rest. Jet lag, on the other hand, can linger for up to 1.5 days per time zone crossed.
6. Skip the quick fixes
Prescription sleeping pills may help you fall asleep, but they do nothing to reset your circadian rhythm. Worse, they can mask symptoms without addressing the cause. Caffeine and alcohol should also be used sparingly: both interfere with sleep quality and circadian recovery.
7. Adapt to the new time zone immediately
Above Adjust to the new time zone immediately instead of giving in to your body’s signals. (Photo: Jcomp / Freepik)
Adjust to the new time zone immediately instead of giving in to your body’s signals. (Photo: Jcomp / Freepik)
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Unless your trip is less than two days, commit fully to local time as soon as you land. Eat, sleep and work based on the destination schedule, not your body’s current signals. Social cues and meal timing help your internal clock adjust. If you need to nap, keep it under 30 minutes and avoid doing so within eight hours of bedtime. With careful timing of light, melatonin and sleep, most travellers can recalibrate their circadian rhythm in a few days. Just don’t wing it: your body clock doesn’t respond well to guesswork.
Chonx Tibajia is a senior editor at Tatler Asia’s T-Labs team, where she writes widely on lifestyle subjects including beauty, style, entertainment and travel. She has a long career in journalism, including roles as a columnist at The Philippine Star, and is the founder of the creative platform Pineappleversed. Beyond Tatler, her bylines appear in regional lifestyle and business publications, showcasing a broad portfolio that spans beauty trends, travel guides and culture pieces.
