Your body may fight you, but when you arrive in Rome, do as the Romans. That is, sleep and eat according to the new time zone, not the old one. If your flight touches down at eight in the morning and you head straight to bed, you can be sure that you'll be wide awake at four the next morning. If you absolutely must get some sleep, limit yourself to a nap of less than two hours. If you're starving at three in the afternoon, have a light snack and wait until dinner-time for a real meal. Other steps you can take include:

Heading outside: Daylight has a direct effect on the body's circadian rhythms, and walking outside can help you stay awake until bedtime and at the same time give you jump start in adjusting to the new time zone.

Getting exercise: Like daylight, moderate to vigorous exercise will give you more energy and, if necessary, help you stay awake until the evening hours. In addition, evidence has been found that exercise allows the body's circadian rhythms to adjust more quickly. If you can't spend an hour on a treadmill, take long walks (perhaps you'll be able to take in some sights on the way!).

Sleep aids at bedtime: When it's bedtime in your new destination, and you find yourself wide awake, get between the sheets, turn out the light and try to sleep anyway. The wear and tear of travel might just catch up with you. Also consider stretching, meditating, taking a hot bath, or engaging in any other activity that deeply relaxes you.

If none of these tricks yields results, you might consider taking melatonin or a conventional sleeping pill for the first night or two, just to get back on schedule. But only do so under the guidance of a physician.

Like the common cold, jet lag has stealthily eluded a sure cure. But even if science never defeats circadian dischronism, you might be able to battle it to a draw--with a little strategic planning.