Newswise — Whether you're hopping a plane to Europe, loading the kids into the minivan for a trip to the Grand Canyon, or heading to a cabin in the woods, summer vacations are all about getting away and having a good time.

And while you're packing and preparing, don't forget one travel essential: a good night's sleep.

With all you want to see and do, away from your usual bed, it can be hard to fit sleep in. But nothing ruins a vacation faster than a cranky sleep-deprived child, a jet-lagged world traveler, or worst of all, a car crash caused by drowsy driving.

Fortunately, says a University of Michigan sleep specialist, there's a lot you can do before and during your trip to help keep those problems from happening.

"Sleep can be pretty disrupted during the summertime for many travelers, and the sleep disruption can start even before travel begins," says J. Todd Arnedt, Ph.D., a sleep psychologist who directs the Behavioral Sleep Medicine Program at the U-M Health System. "But if you can maintain good sleep practices, you'll find that your vacation will be more enjoyable because you'll feel more rested during the daytime."

The whole idea of traveling clashes with a lot of the regular habits and schedules that are needed for good sleep. A comfortable bed, a regular bedtime, a calm evening and a quiet dark room all make it easier for kids and grown-ups to get to sleep and get a full night's rest.

But vacations can turn all of those good sleep habits on their head. Our routines get disrupted, we stay up late to squeeze in more sightseeing, and when we finally hit the sack, we're in a strange environment and thinking about the next day's adventure. Add in a change in time zone, or a little extra alcohol or stress, and it's a recipe for a restless night — which often means a very sleepy next day.

The bottom line for any traveler, Arnedt says, is to try for as normal a sleep routine as possible, including adjusting that routine for changes in time zone. And if you're driving during your vacation, it's important to know the signs of drowsy driving and pull off the road before you get in an accident.

In some people, he notes, sleep problems that begin or worsen during a vacation might not go away after they return home. Insomnia, and the psychological effects such as frustration that can result, may linger long after the vacation ends.

So, what can a traveler do? Arnedt offers this information and advice:

For vacations into other time zonesWhether you're crossing the continent or flying to another part of the world, the "jet lag" that results from adjusting to a new time zone and then adjusting back to your usual one can really be a hassle. Your body's internal clock, which helps regulate everything from hunger pangs before meal time to your mood, gets out of whack when a few hours "disappear" from your day, or are added to it.

A lot of this has to do with the amount and timing of exposure to light. Our brains produce a hormone called melatonin in response to the light and dark cycles we experience; it helps tell the rest of the brain and body that it's getting close to bedtime.

"Melatonin is our 'darkness' hormone, and when our brain thinks it's nighttime, it starts to produce it," explains Arnedt, a member of the U-M Sleep Disorders Center and an assistant professor of psychiatry and neurology at the U-M Medical School. "There's a relationship between when melatonin starts being produced in the brain, and when our bodies most feel like being asleep."

But when those light and dark cycles are disrupted, so is melatonin production " and our sleep patterns. Thankfully, you can reset your biological body clock, also known as your circadian rhythms. As soon as you get to your destination, or even in the days leading up to departure, expose yourself to the "cues" that tell your body what time it is in the new time zone.

"That usually involves exposure to light in the new time zone, and increasing activity at the appropriate times during the day so that your body learns to adjust and live on that different time schedule," Arnedt explains. You can also buy a pill form of melatonin, which some people have found can help the adjustment further.

For vacations that involve drivingThe great American road trip can turn tragic in an instant, if the person behind the wheel is sleepy.

A new National Highway Traffic Safety Administration study concludes that being drowsy increases a driver's risk of a crash or near-crash by at least a factor of four " and that's only using data from crashes where police reports mentioned a sleepy driver. Many more crashes and near-misses may be due to drivers who nod off or are less than alert.

"Driving while drowsy is the single greatest sleep hazard associated with driving trips, and more than 50 percent of individuals in major surveys say they drive drowsy in any given year," says Arnedt. "A conservative estimate shows that more than 100,000 crashes, 71,000 injuries and more than 1,500 fatalities each year are due to driving while drowsy, and some estimates say 25 percent of all accidents may actually be attributable to it."

Arnedt's own research shows just how badly driving ability can suffer from lack of sleep. He led a study of young doctors who work long hours and compared their driving-simulator performance after an on-call night at the end of a heavy call month with their performance at the end of a light call month after having a few alcoholic drinks. The study found that when they were sleepy, the doctors performed just as badly as they did when their blood alcohol level was 0.05 g% — just under the legal limit for driving while impaired.

Getting good sleep is the first step to avoiding drowsy driving " and drivers who know they have a long trip ahead of them in the morning should feel no shame about calling it a night, even on vacation. Their passengers should encourage them to do so, for everyone's safety.

Once you're on the road, how do you know when it's time to pull over and rest?

"If your head is bobbing, you're yawning, or your eyelids are drooping, those are signs. If you're drifting into another lane, zoning out and missing exits, or driving on rumble strips at the side of the road, those are red alerts," says Arnedt. Another danger sign: trouble remembering the last few miles you drove.

Then, he says, "It's imperative to get off the road and engage in one of the two strategies we know are effective: taking a nap or having a dose of caffeine, or both." And though coffee can keep you going for an hour or two more, it's no substitute for adequate sleep.

For any vacationerEven if you've left the driving to someone else and you're staying in your time zone, it's still important to get good sleep on vacation.

Arnedt recommends lots of activity and sunlight during the day, a comfortable bed in a dark room at night, cool nighttime room temperatures, and a sleeping location away from noise or distractions. He also says it's best to avoid daytime naps even if you feel sleepy from all that running around; this can disrupt your nighttime sleep.

If you're drinking alcohol or caffeinated beverages a little more than usual on vacation, don't overdo it " or drink them too close to bedtime. Both substances can alter sleep patterns by making you wake up in the middle of the night or creating trouble falling asleep.

And if you do have trouble sleeping, don't just lie there worrying, he advises. "Get out of bed, don't get frustrated about your sleep, and wait until you feel sleepy again," before getting back in the sack, he says.

If you know from experience that you can't sleep in a strange bed or if a few sleepless nights have gone by, an over-the-counter or prescription sleep medicine might help. But, Arnedt stresses, these should be used only as needed " the side effects and daytime impacts of many sleep aids used over the longer-term aren't yet full understood.

Facts about sleep habits, drowsy driving and jet lag:"¢ Important factors for getting a good night sleep include: a regular bedtime even on weekends; a quiet, dark room with a comfortable mattress and pillows; and avoidance of alcohol, caffeine, tobacco, meals and exercise within a few hours of bedtime."¢ Moderate or severe drowsiness was cited as a factor in 22 to 24 percent of the vehicle crashes and near-crashes in a recent real-world government-sponsored driving study."¢ National polls performed by the National Sleep Foundation show that 60 percent of adult drivers and 51 percent of teenage drivers drive drowsy at least once a year — and 14 percent of adults and 15 percent of teens said they drive drowsy at least once a week."¢ NSF polls also reveal that 37 percent of adults and 5 percent of teens said they had nodded off or fallen asleep at the wheel within the past year. "¢ Jet lag occurs when the body's biological clock is out of sync with local time, and affects millions of travelers each year. Its symptoms typically last longer after eastward flights, which interfere with the start of sleep; flying west leads to early morning awakenings. All age groups are susceptible, but people over age 50 are more likely to develop jet lag.

Find out more on the web at: University of Michigan Sleep Disorders Centerhttp://www.med.umich.edu/neuro/sleeplab/

U-M Sleep & Chronophysiology Lab http://www.med.umich.edu/depression/sleeplab_index2.htm

National Sleep Foundation Drowsy Driving site http://www.drowsydriving.org

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