Vacationing somewhere far from home is always fun — but traveling there via plane can be a real lesson in self-discipline. Hours upon hours in a cramped, confined space with low air pressure and low humidity can bring on discomforts ranging from headache to dehydration.
No surprises there.
But even after stepping off the plane, your troubles may be only beginning. While the symptoms of travel fatigue fade fairly quickly, the icky feelings that accompany jet lag — irritability, indigestion, sleepiness during the day and insomnia at night — can last for days or even weeks if you don’t play your cards right.
For frequent flyers like pilots and flight attendants, jet lag can even become a chronic problem. In the long term, it’s associated with increased risk of things like cardiovascular disease, diabetes and Alzheimer’s disease.
“Before the airplane was invented and international flight was introduced last century,” says Greg Roach, a professor at the Appleton Institute for Behavioural Science in South Australia, “there [was] no need for our circadian systems to immediately adapt to rapid time zone changes.”
Of course, that doesn’t mean it’s not possible — within reason.
Roach and his colleagues have spent plenty of time advising athletes, coaches and sports psychologists on how best to minimize jet lag prior to important competitions like the Olympic Games or World Cup. Luckily for us, his tips and tricks apply to non-athletes, too.
What Is Jet Lag?
Jet lag occurs when your circadian system, or body clock, is out of sync with your new surroundings.
Human circadian rhythms operate on a roughly 24-hour schedule and influence a whole bunch of background physical, mental and behavioral processes that you don’t typically worry about — until you fly across three different time zones, of course.
The system reaches its lowest point around five hours into a good sleep session. For most of us, that’s somewhere between 3 a.m. and 5 a.m.
At this point, your body is behaving very differently from how it does while awake; in fact, even your core body temperature is at its lowest point during this time. Then, when morning light enters your eyes and travels along the optic nerve all the way to the circadian center, the brain tells you that it’s time to wake up and be alert.
Read More: How Your Circadian Rhythms Control Your Every Waking — and Sleeping — Moment
How to Reset Circadian Rhythm
What does all this have to do with jet lag? “The greatest misconception,” Roach says, “is that the best approach to minimize jet lag is to get as much sunlight as possible in the new location.”
Light Exposure and Jet Lag
As a general rule, it’s fine to soak up as much sun as you want when traveling east to west because the sun sets before your circadian rhythm naturally reaches its low point. In this case, your internal clock reads sunlight as a “delay” signal — essentially, it now knows it should slow down in order to match what’s happening in its environment.
To help ensure your body gets the message, Roach suggests basking in the sun without sunglasses or spending time in a brightly lit room in the hours just before your biological clock’s natural low point.
Traveling west to east, unfortunately, is often far more complicated.
Say you've traveled from Los Angeles to London and your circadian low point is now around noon local time (yikes). If you decide to catch as many rays as possible both in the morning and afternoon, your circadian system will subsequently receive both a “delay” and “advance” signal (double yikes).
“The result is that your body clock gets stuck in a state that is not aligned with local time, so you will be sleepy during the daytime and you will sleep poorly at nighttime,” Roach explains.
Instead, he suggests completely avoiding light in the morning and then lots of light exposure in the hours after your internal clock’s low point to speed things along.
Melatonin for Jet Lag
The ultimate goal, of course, is to shift your daily circadian low point until it occurs while you’re actually sleeping at night. If you do become tired during the day, however, you might be tempted to rely on a quick cat nap.
Limit these naps to less than 30 minutes and take them at least eight hours before your planned bedtime; anything else could throw off your sleep schedule even more. As an alternative, Rush University Medical Center researchers Charmane Eastman and Helen Burgess suggest taking 1 to 3 milligrams of melatonin two hours before bedtime.
In fact, try both light exposure and melatonin if possible. Their effects, according to various studies, are additive — meaning that using both tools at the same time tends to produce a greater effect and helps you adjust to time zones faster.
But where melatonin really outshines the sun is in its ability to shift your body clock in the days leading up to a flight, too. If you’re planning to travel east to west, Roach recommends taking a small amount of the supplement after your circadian low point — whenever you wake up in the morning — to preemptively tell it to slow down.
Traveling west to east? Do the opposite: Take some melatonin in the hours leading up to bedtime, for a few days, to prepare your circadian system to speed up.
Read More: Does Melatonin Cause Dementia?
How to Get Over Jet Lag
Beyond light, there are other environmental stimuli that influence our internal clocks, too. Researchers call these zeitgebers, and they can include things ranging from temperature to social interactions.
If light exposure and melatonin aren’t quite doing the job, try the following:
Socialize to improve mood and stay alert.
Eat meals according to the local schedule.
Exercise during the day, even if that means taking the stairs instead of the elevator.
Skip alcohol and caffeine before bedtime.
Finally, it’s important to acknowledge that no matter what you do, your body simply won’t be operating at its peak performance for a while — whether you’re a professional athlete or not. Unnecessary physical and mental stress will only make things worse.
Therefore, adjust both your sightseeing schedules and personal expectations accordingly, at least for the first few days. Odds are, you'll still find plenty to enjoy.
Read More: The Biology of Stress In Your Body