We like to think we have control over our bodies, but the opposite is often true. Such is the case with circadian desynchrony, commonly known as jet lag. Exhaustion. Gastrointestinal discomfort. Headaches. Difficulty concentrating. Trouble falling asleep or staying asleep. These common jet lag symptoms have the power to put a damper on a dream vacation. Unless you figure out how to game your own system.

Senior experimental psychologist John Caldwell has spent the bulk of his career researching the effects of sleep deprivation and sleep restriction, while also studying countermeasures that sleep-deprived people can use to function better.

Caldwell explains that while our bodies are able to adjust to about one time zone change per day, jet lag sets in when we cross three or more of them, because it wreaks havoc on our circadian rhythms. "We just haven't evolved to the point where we can rapidly change those rhythms," he said.

While you can't banish the effects of jet lag completely, scientists and physicians agree that there are things you can do to help adjust to a new time zone more quickly. Here's what the professionals suggest.

Align your sleep schedule with your destination

Because your body can naturally adjust to about only one time zone change per day, you'll want to manually adjust your schedule, and that means changing your bedtime to better mesh with the destination to which you're traveling.

Ranit Mishori, a professor of family medicine at Georgetown University, travels frequently to Europe, Africa and the Middle East. To be ready to hit the ground running when she arrives, she starts adjusting her bedtime two to five days in advance to match the local time at her destination. "That means going to bed earlier when going east and waking up much earlier," she said. "When I come back to the U.S., I do the same but in reverse."

Caldwell creates a timetable so that, at a glance, he can see what time it is at home and at his destination and plan accordingly. "A lot of times, when you look at that table, right away you're going to see where you're going to have your biggest problems," he said. If he'll be gone only a couple of days, he avoids gradual adjustment. Instead, he tries to plan any meetings at a time when he would be awake and alert back home.

Time your light exposure right

Circadian rhythms are influenced by sunlight. While travel may make those rhythms hurly-burly, you can help get them on track with exposure to or avoidance of light, said Pradeep Bollu, associate director of the University of Missouri Health Care Sleep Disorders Center. When traveling east, your biological clock will be behind. "Melatonin and avoiding bright light in the evening can help with advancing our biological clock," he said. "Similarly, bright light exposure after waking up also will help advance our biological clock to suit the new time zone." When traveling westward, he added, the biological clock is ahead of the latest time zone. He suggested gravitating toward bright light in the evening and exercising to stay awake later and sleep longer.

An online calculator such as jetlag­rooster.com can also be helpful. It provides a brief plan to avoid jet lag, sharing the ideal time to get to sleep and the ideal time for light exposure.

Pack the melatonin

A number of physicians suggested taking melatonin, a hormone produced naturally in the body that helps you sleep. "Taking a very small dose helps to recalibrate its release so that it is in sync with the time zone of your destination," said Dr. Kern Singh, a spine surgeon in Chicago. He said he takes 5 milligrams of melatonin on the plane and then again when he lands. "I time the dosing depending upon the time zone of my destination. For example, if I am leaving for Europe and it's 3 p.m. in Chicago but it's 9 p.m. in London, I take the melatonin right away so I fall asleep at the appropriate time of where I am traveling to," he said.

Turn your wine into water

Having a glass of wine or two on the plane may sound tempting, but it could hurt your sleep, which could worsen jet lag, said Quay Snyder, president and CEO of Aviation Medicine Advisory Service of Centennial, Colo., who advises pilots on staying in top condition while in the air. "It definitely has a sedating effect as far as getting someone to sleep, but it destroys their rapid eye movement [REM] sleep so their actual mental recovery is reduced," he said. Instead, he said, be sure to drink plenty of water so that you stay hydrated while traveling.

Seek medicinal help

You can always ask your doctor for some help. Dr. Bruce Stephen Rashbaum of Capital Center for Travel and Tropical Medicine in Washington, D.C., regularly counsels patients on jet lag. He considers prednisone, a prescription corticosteroid, to be the most effective tool for jet lag recovery. He instructs patients to take the medication when they land, typically early in the morning, and again in the late afternoon and the next day. "Our bodies have a gland called the adrenal, which releases a prednisone equivalent around 5 a.m. and 5 p.m.," he said, adding that a little extra prednisone, by prescription, mimics what the adrenal gland would do on its own and can help reset the body's clock. "It is this simple ritual that works nearly every time," he said.

Caldwell, the sleep researcher, said if he has a meeting or presentation abroad, he's not averse to using prescription medications to help him sleep. "I'm actually not a medication-phobic person, so my go-to is sleep medication at night with lots of caffeine during the day," he said.

Everyone responds to jet lag differently. For those who suffer, the first week will usually be the most challenging, but your body should start to bounce back. Maybe it's the excuse you need to book that longer vacation and make the most of it.