Use light to take the lag out of jet-setting


Most frequent travelers have experienced a debilitating bout of jet lag or two and could attest that the syndrome can really put a damper on a trip.

Luckily there are some simple ways to trick the body into adjusting more quickly to a new time zone to keep alert during precious vacation days.  

“When we rapidly cross time zones, we can experience circadian misalignment in which the circadian rhythms are out of sync with the environment,” said sleep researcher Jay Olson.

“Cross 12 hours and now you feel most fatigued and cold in the middle of the afternoon, which is no longer ideal,” he said. “This misalignment is called jet lag.”

Natural rhythm

Jet lag happens when someone travels across time zones quickly without their body’s circadian rhythm having time to adjust naturally.

“Circadian rhythms are roughly 24-hour cycles that influence sleep, alertness, hormones and various other physiological processes,” Mr. Olson said. “Usually, these rhythms are in sync with our environment.”

The body uses sunlight as a signal for how much melatonin, a hormone that helps to induce sleep, to produce – amounts are very low during the day and high at night.

When the timing of day and night changes drastically, it can take a bit for the brain to catch up, resulting in the dreaded jet lag. The body expects to be sleeping when it is supposed to be awake and vice versa, which can cause fatigue, disorientation, stomach issues and mild illness.

According to the American Academy of Sleep Medicine, it takes about one day per time zone crossed to adjust – the greater the time change, the longer it will take to get over.

Also, the farther east one moves, the worse symptoms will be.

“Travelling a few time zones east is harder than travelling a few time zones west, since it is typically harder to shift the circadian rhythms earlier rather than later,” Mr. Olson said. “I think of it like this: if you usually fall asleep at 11 p.m., it’s harder to fall asleep two hours earlier at 9 p.m. than it is to stay up a couple hours later.”

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Light the way

Unfortunately, those on a short holiday do not have time to allow themselves to fully and naturally adjust to a new time zone.

Using light, both before and during a long-distance trip, is the best way to trick the body into catching up quickly.

“Controlling your light exposure is the most studied way to prevent jet lag,” Mr. Olson said.

Before a trip, “if travelling a few time zones east, getting bright light after you wake up and avoiding light exposure before bed can shift your circadian rhythms to help match the destination,” he said. “If travelling a few time zones west, get light exposure before bedtime and avoid it in the morning.”

Timing can be tricky though when trying to adjust ahead of a vacation.

“When crossing more than a few time zones, the light exposure times become a bit more complicated – more preparation is needed and sometimes the right time for light exposure is counter-intuitive,” Mr. Olson said.

There is a wide variety of Web sites and apps, such as Jet Lag Rooster, which Mr. Olson helped develop, that will compute exactly when you need light or darkness in local time.

Artificial sunlamps are a good way to stay bright after nightfall. And, if darkness is needed while it is still light out at home, drawing the shades, staying in a basement and wearing sunglasses when outside can help.

Melatonin supplements can help with sleeping at unusual times.

Upon arrival, light exposure is still the best way to wake up, especially when combined with exercise – another trick for combatting jet lag’s effects on a trip.

Other than light, “drink a lot of water, eat fruit, shower and take a short nap,” Mr. Olson said.

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