What Really Happens When You Get Jet Lag
Few things squelch the excitement of arriving at a new, far-off destination more than falling asleep over your first taste of local cuisine. But for most travellers flying over more than two or three time zones, experiencing jet lag is unavoidable and a likely scenario. Our internal body clocks, aka circadian rhythms, just can't keep up with travelling at 575 mph for very long.
Natalie Dautovich, Ph.D., an Environmental Fellow at the National Sleep Foundation, explains "Jet lag occurs when we experience a desynchronization between our internal body clock and the external time clock of our destination. Symptoms of this desynchronization include fatigue, difficulty sleeping, difficulty concentrating, indigestion, and a negative mood" (via Travel and Leisure).
Scientists have studied the body's complex circadian rhythms at the cellular level, and found that cells actually have their own internal clocks, which respond to differences in light, and allow organisms to anticipate changes in the environment by pacing their metabolisms to external light cues. This can explain the sense of winding down that we feel in the evening, even before we would normally go to sleep (via Science Daily).
When our inner body clocks are out of sync with our external environments, we experience the unpleasant symptoms of jet lag, until our cells adjust and reset themselves to our new environment.
Getting outside during the day can help with jetlag
For most people, their body clocks run on an approximately 24.5-hour cycle. That preference for days that are slightly longer than our standard 24 hours might explain why jet lag is usually worse for people travelling east, when hours are taken off the day, than it is for those travelling west, when hours are added to the day (via Washington Post).
There are a few simple ways to help at least minimize the unpleasant symptoms of jet lag. Since exposure to light is the main element that influences our body clocks, getting outside in the morning and during normal daytime hours in the new location is important for quickly adjusting to the new time zone. Avoiding alcohol and caffeine on the flight, as well as staying comfortable and hydrated, can also help.
Frequent travelers also recommend being preemptively proactive, by adjusting your sleep schedule ahead of traveling. Ranit Mishori, a professor of family medicine at Georgetown University School of Medicine, travels between continents often. She suggests adjusting your bedtime two to five days before traveling. She says "That means going to bed earlier when going east and waking up much earlier. When I come back to the U.S., I do the same but in reverse" (via Washington Post).