VOA健康报道2024--How to Prevent Jet Lag, Enjoy Travel

（单词翻译）

Many travelers face a common problem: jet lag.

It is the feeling of tiredness people get when traveling a long distance, resulting in a difference in daylight hours. Nobody wants to miss the fun because they are too tired to enjoy their vacation.

Here are some tips on how to deal with jet lag:

What is jet lag?

Scientists define jet lag as the effect on the human body of traveling across time zones. Sofia Axelrod studies circadian rhythms at Rockefeller University in New York. She said a circadian rhythm is like a biological clock programmed into almost every cell in the body.

"The clock is set by the 24-hour light and dark pattern," Axelrod said. "Every morning when we wake up, specialized¹ (light) receptor cells in our retina receive a daylight signal, which is transmitted to the brain and from there, (to) the whole body."

When we travel to another time zone, our eyes do not receive the daylight signal at the usual time. This causes our "internal clocks" to reset². But that process can take a while. During that period, we feel the effects of jet lag.

Is jet lag preventable?

People who travel long distances often want to prevent jet lag. One way has a high cost.

Malcolm von Schantz is a professor who specializes in circadian rhythms at Northumbria University in Newcastle, England. He said that paying a lot for a bigger seat and more space in an airplane can prevent sleep deprivation³.

He knows most people cannot pay so much to travel. But he said timing⁴ your flights can help. For example, he suggests flying from Europe to North America during the day, so that it is evening when passengers land and they can get to sleep.

"If you take the evening flight instead, you'll be woken up at midnight to be served breakfast and land an hour or two later, when both jet lag and sleep deprivation will hit you hard," he said.

Von Schantz also said flying in newer model passenger jets, like the Airbus A350 or Boeing 787 Dreamliner, might help. He said those planes can maintain a more comfortable atmosphere inside, causing less tiredness.

What should you do when you arrive?

Experts say being in sunlight is important to resetting⁵ your internal body clock. That could mean either avoiding morning sun or seeking it out, depending on where you started.

Getting light in the morning will move your body clock forward, while light exposure in the early evening will delay it. Sleeping for a short time during the day is acceptable, but scientists warn against sleeping for longer periods later in the day. Doing so might make it harder to sleep through the night.

Are there supplements or medicines for jet lag?

The brain naturally produces a chemical hormone⁶ called melatonin when the body thinks it is night. Taking melatonin as a supplement can be helpful. But it is not available everywhere and, in some countries like Britain and France, you need a doctor's permission.

Von Schantz said that one of the good effects of melatonin is that you can start taking it before you travel, to begin the process of resetting your internal clock.

"If you're in a part of the world where melatonin is available over the counter, you can combine the effects of light and melatonin to achieve the advance or delay (in your body clock) that you need," he said.

What can you do to deal with the effects of jet lag?

Russell Foster of Oxford⁷ University wrote a book on circadian rhythms. He said business travelers might want to consider arriving a day or two ahead of any important meetings or events. Being jet-lagged can lead to unwise decisions and unpleasant emotions.

Tourists might not need to think as clearly as business travelers, but they should still be careful, he said. He advises tourists to get enough sleep before doing anything that might be risky⁸ or that requires a lot of attention, like driving.

Foster said he tries to increase his exposure to light when he arrives at a new place to prevent jet lag. But he also has another method if light does not help: he drinks coffee.

Words in This Story

jet lag - n. a tired and unpleasant feeling that you sometimes get when you travel by airplane to a place that is far away

time zone - n. any one of the world's 24 divisions that has its own time

circadian rhythm - n. repeated activity in an organism that happens in 24-hour periods

pattern -n. a regular or repeated happening

retina - n. the sensitive tissue at the back of the eye that receives images and sends signals to the brain about what is seen

deprivation - n. the state of not having something that people need

comfortable -adj. to feel good and to not feel pain or discomfort⁹

hormone -n. a chemical produced by the body that influences how the body grows and develops

over the counter - expression. available for purchase without a special note (called a prescription) from a doctor