by Shawn L Fitzpatrick
What does Jet Lag do to our bodies to make us feel so wiped out?
Your body secretes hormones at certain times of day, and your brain expects different hormones to be at work at certain times. For example, cortisol, a stress hormone, rises in the morning when you’re about to start your day and face the world. The growth hormone is produced at night. This is all controlled by the endocrine system, and the timing of these hormones helps your brain know whether it’s day or night—based on the previous day and night. But when you travel, all of a sudden you’re awake when your body is supposed to be asleep, or vice versa. So your behavior is out of sync with your body’s hormones and the endocrine system. And the end result is that you just don’t feel right. You can function, but you’re not at your sharpest; you have a malaise, your thinking is a little fuzzy, you might get a headache or a stomachache; your body is out of sync with itself.
It takes about three to five days to get over jet lag—and the more time zones you skip, the more severe the jet lag will feel. There are ways of minimizing jet lag, but no matter what we do, our brains aren’t meant to take such huge shifts—3, 6, 12 hours if you go abroad—in our schedules.
How are we affected differently depending on which direction we are traveling?
The circadian system is the part of the brain that deals with biological activity around the 24-hour cycle. More specifically, there’s a little piece of tissue behind the eye, where the optic nerves crisscross, called the suprachiasmatic nucleus (SCN), that helps coordinate all the various biological rhythms of the cells in our bodies. The SCN measures time and acts like a conductor—letting all the cells in the body know what time the sun is expected to come up tomorrow based on when it came up today.
A quirky thing about this clock in our head is it’s not a 24-hour clock; it’s about a 24-hour-and-10-minute clock. It overshoots. (This is true for almost all of us, although a few people do have clocks that are a bit shorter—these people tend to have a hard time staying up late.) We also get a surge of alertness in the evening that’s modulated by this conductor, too. And because of this it’s always easier for you to stay awake later than it is to go to bed earlier. Let’s say your normal bedtime is midnight—it’s going to be easier for you to go bed at 2 a.m. than 10 p.m.
If you apply this to jet lag, it makes more sense that we are affected differently depending on which direction we are headed. If you’re going east, you are going to a shorter day—you have to go to sleep earlier. Going west, your day is extended, you get to stay up later—easier because you are adapting to prolonging the day. A friend of mine taught me this saying about traveling: East is a beast and west is best. It’s true, but when you’re doing really long trips, making big jumps in time, you’re going to get messed up in either direction.
How do we use this knowledge to our advantage when it comes to planning our travel and tackling jet lag?
To start, think about which way you’re traveling, how long you will be spending at your destination, and the purpose of your trip.
If you are going somewhere for more than five days or so, you may want to begin adapting to your destination’s time zone before you leave. You do this in 15-minute increments—so if you were going to New York from California, you would go to bed 15 minutes earlier on the nights leading up to your trip, as practical and possible. But, if you’re only going to be away for a few days, it’s best to keep your local time zone, and deal with the jet lag while you’re away.
Dr. Rafael Pelayo of the Stanford Center for Sleep – wants you to keep in mind Five Critical Moments to better plan your trip and manage jet lag:
1. The time you usually get up.
2. The time you usually go to bed.
3. The time you are most awake—generally two hours before you fall asleep, when your temperature rises.
4. & 5. The two times you are the sleepiest—generally around 2 p.m. and two hours before you wake up, when your temperature drops.
Figure out what those times are for yourself in your local time zone, and plan out accordingly (as much as you can) in your destination time zone. For example, if you’re scheduling a business meeting, do it when you’re normally most alert in your home time zone—about 2 hours before your usual bedtime. Avoid a meeting when it’s just after lunch in your local time zone—if you’re sleep deprived, catch a nap during this time if you can. If you can’t nap, plan to exercise—a good way to chase away sleepiness and help you sleep better at night. The same logic applies if you’re a tourist—don’t plan a sedentary bus tour when your body is going to be sleepiest; you want to do that when your brain is more active.
You can also use light or darkness to help you change time zones, although it is difficult to make big changes in a short amount of time just relying on light. For instance, you’ll see people wear sunglasses on the plane to signal to their bodies that it’s night and to help get some sleep. And then, when you land at your destination, it’s a good idea to take in some bright light during the day to help you reset your clock. Usually, if you want to adapt quickly to your new environment, you try to get as much light in the morning at your destination as you can. But if I’m traveling to New York from California for a short trip, and I want to actually avoid getting on NYC time since I’ll be back in California so soon, then I want to minimize my light in the morning.
For short trips during which you don’t really need to adapt to a new time zone, depending on the purpose of the trip, I also recommend that people attempt to do activities in their local time zones as much as possible—particularly when you’re visiting a city that is busy around the clock. For instance, if you’re traveling east, maybe you become more of a night person during your trip. If you’re heading west, check out the sunrise.
“Do not go where the path leads, travel instead where there is no path and leave a trail.” @wbbrjp