The man-made marvel of the 20th century, the airplane, allows a traveler to be on opposite sides of the earth on the same day! However, there is a price to pay when crossing time zones - a disorientation of body rhythms and time sequence.

The time difference between the point of embarkation and disembarkation can throw one's sleeping, waking, eating and working routines into chaos; and this can take days, even weeks, to correct. Symptoms of jet lag include dizziness, lethargy, nausea, insomnia, light-headedness, muscular weakness and a general feeling of ill health.

If you follow the guidelines below, traveling should be easier and will certainly be more enjoyable. "Pleasant dreams!"

Psychological Time Adjustment
If your next trip involves a large time hop, try following these tips. Set your watch and time schedule to those of your destination. A "mind over matter" effect takes place and your body rhythms tend to follow in line with your thoughts. Choose a late departure time when flying west and an early departure time when flying east.

Meal and Sleep Adjustments
On board the plane, you can begin to adjust sleeping and eating habits according to the schedule of your destination. While most airlines serve meals according to the time schedules of the port of origin, it is left to you to adjust your own meal times to your destination schedule.

It may be helpful to take a high protein breakfast and lunch, and a high carbohydrate supper to ensure a wakeful day and restful night. When it is night at your destination, wear a sleep mask and try of sleep. If it is day, turn on the light above your seat and try to stay awake.

Flying at high altitudes, where the air pressure and humidity in the cabin are lower than on the ground, can leave you dehydrated at the end of the journey. This could make you feel more tired and lower your body's resistance to illness. Avoid alcoholic drinks and drink lots of water.

Follow Local Timetable on Arrival
If you arrive in the morning, try to stay outdoors and keep active. Eat light meals during the day and drink plenty of fluids, so that you do not overwork your digestive system. If you arrive at night, take a hot drink (without caffeine) and go straight to bed. By forcing your body to follow these strict rules, you speed up your internal body clock to keep pace with the local timetable.

Melatonin
Recent research has demonstrated that taking melatonin in pill form may help limit the effects of jet-lag. Melatonin is a hormone secreted by the pineal gland in the brain, which is stimulated by darkness and inhibited by light. There is evidence that a small dose of melatonin will delay the daily clock when taken in the morning and advance it when taken in the early afternoon or evening. The suggested dose 3-5 mg (don't buy mcg or micrograms). Take one 3-5 mg tablet the day of the departure, one hour before the bedtime of your destination. Take one 3-5 mg tablet for 3-5 more nights at your destination (about 30 minutes to one hour before you want to sleep).

If you want to sleep on the flight, take one tablet 20 minutes to one hour before you want to sleep. For your return trip, reverse the schedule above.