When you fly to Portugal to visit relatives, you no doubt experience an overwhelming tiredness that drags you down and interferes with your holiday enjoyment. Or if you’re on a working trip, this jet lag can keep you from being at your best at that important conference or business meeting.

“Your body can be in Europe but your clock, your circadian system, is still in Montreal or Toronto,” says Dr. Diane Boivin, Director, Centre for Study and Treatment of Circadian Rhythms, Douglas Institute, and Professor, Department of Medicine, McGill University, Montreal.

It takes some time for your clock to readjust to the new time zone. In the meantime, you will experience jet lag symptoms such as daytime fatigue and difficulty concentrating and functioning

Jet lag is generally worse when you “lose time” travelling west to east instead of gaining time by travelling east to west.

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Adjusting to the new time depends on where you travel. If you go to London, England, for example, which is several hours ahead, Boivin recommends trying to sleep on the plane as much as you can, and when you arrive at your destination, to adjust to the new environment “as much and as fast as you can.”

“Force yourself to stay awake throughout the first day and then go to sleep at midnight London time,” she says. The first night will be easier to fall asleep because you will be sleep deprived, but should get progressively easier.

Of course, when the time zone is much different from the one you’re used to – say you’re flying from Montreal to Australia – the adjustment will be more difficult and take longer. It typically takes about a day per time zone change, or per hour change, to get used to the new environment, says Boivin.


Jet lag is generally worse when you “lose time” travelling west to east instead of gaining time by travelling east to west. And it can be worse for older adults who find it more difficult to adapt.

Restless sleep due to excitement about your impending trip in the weeks leading up to your departure can exacerbate the jet lag problem, according to Dr. Rachel Morehouse, medical director, Atlantic Sleep Centre, St. John Regional Hospital, St. John, New Brunswick. “The minute you step on that plane, you’re already sleep deprived, and then you have some alcohol and a meal at midnight, and then you land, and you feel terrible and it’s daytime and you haven’t slept.”

It doesn’t help that you’re cramped in the confined space of an aircraft either. A 2007 study in the New England Journal of Medicine found that air cabins pressurized to 8,000 feet lower oxygen in the blood, making you feel tired and dehydrated. And it’s difficult to move around on an airplane, so you may suffer circulation difficulties. All of these conditions may affect the ability of your circadian rhythm to adapt to the time zone you’re flying to.

Morehouse suggests acclimatising to time zones by getting up and going to bed earlier several days in advance of your journey. She and others also recommend taking steps to optimize sleep habits before you leave, to avoid alcohol on the plane, and to sleep or at least rest en route. And she agrees that when you arrive, it’s important to get on local time right away.

You also might try selecting a flight that lands in the early evening which will make it easier to adapt to the change in time. As well, try bringing earplugs and eye masks to help you get some rest on the plane. Packing familiar items (for example, a picture of your family) to put in your hotel room might help you feel more at home and relaxed, which could improve your chances of falling off to sleep more readily.

You might want to stay away from spicy foods, at least initially. These and rich, fatty foods, especially close to bed time, can interfere with your digestion and keep you from getting a good night’s sleep.

And take a hot bath in your hotel room to relax before bed. Hotels often have sumptuous body lotions to luxuriate in and help you get in the mood for sleep.

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