Better Sleep on Business Trips (cont.)
Traveling Over Time Zones
Flying across time zones changes the principal time cue -- light -- for setting and re-setting our 24-hour, natural day-night cycle, or circadian rhythm. Our internal clock becomes out of sync or mismatched with our current day-night cycle. Our circadian rhythm greatly influences when we sleep, and the quantity and the quality of our sleep. It may also be altered by the timing of various factors, including naps, bedtime, and exercise.
In general, "losing" time is more difficult to adjust to than "gaining" time. Traveling east we lose time; west we gain. An "earlier" bedtime may cause difficulty falling asleep and increased wakefulness during the early part of the night. Going west, we fall asleep easily but may have a difficult time waking.
Generally, it takes about one day to adjust for each hour of time change. A trip across one time zone for a couple of days should not cause much of a problem for most people.
You can re-set your internal clock to adapt more quickly to the time changes. Your circadian rhythm is internally generated but is influenced by the environment, behavior, and medications. It is important to expose yourself to the light during the waking hours as much as possible, and conversely, do not expose yourself to bright light when it is dark outside. Even the light from a computer screen or turning the light on in the bathroom in the middle of the night can adversely affect your sleep.
Take steps before your trip to ensure you'll get adequate sleep on the road.