A Restful Journey

by Dr. Michael Breus, PhD

Who is ready to get back out in the world? We’ve spent a long time tied closely to home. But travel is once again on the horizon.

Travel can do a real number on your sleep. But it doesn’t have to. With planning and preparation, along with some basic sleep knowledge, you can protect your sleep, even during the most rigorous and far-flung journeys.

The major underlying source of travel- related sleep problems? Disruption to circadian rhythms. These 24-hour biological rhythms regulate sleep and much of the body’s physiological functioning, and they’re controlled by a master circadian clock in the brain, the keeper of our biological time. When circadian timing is out of sync, sleep gets disrupted.

Travel interferes with circadian timing in a couple of ways:

Exposure to light at the wrong times.

Light and darkness have a dominant influence over circadian clocks and rhythms, sending powerful cues to our master circadian clock. Darkness stimulates the production of melatonin, which regulates sleep-wake cycles and is involved in regulating our daily circadian rhythms. When we’re exposed to light (natural or artificial) at close proximity to the times when our bodies are biologically primed for sleep, melatonin is suppressed, we can’t initiate sleep and circadian timing gets thrown off course.

Being awake and active when you’d normally be sleeping.

The mismatch of social time and biological time that happens when we move through time zones and leave our normal routines, can put circadian clocks
out of alignment. Jet lag is the result of this misalignment between social time and our internal circadian timing. Jet lag is, of course, most closely associated with long-distance travel, but even short trips can induce “social jet lag,” when we’re suddenly living and sleeping out of sync with our typical schedules.

Our circadian clocks don’t all run on exactly the same time. We have different biological tendencies for sleep and activity in the earlier or later phases of the solar night and day. These differences in circadian timing arise from our genetically determined individual chronotype.

Your chronotype will affect how you respond to travel. Early chronotypes, the Lions of the world, will generally have an easier. time traveling east through time zones. Late chronotypes, the Wolves among us, usually have an easier time with westward travel. Understanding your chronotype can help you make specific plans for travel—scheduling flights, timing your sleep and managing light exposure en route, creating a new temporary schedule for sleep and activity at your destination—that will minimize circadian disruption and sleep loss. Here’s how to determine your chronotype.

While always keeping your individual chronotype in mind, the best strategies to avoid circadian disruption and sleep loss depend on the distance you’re traveling.

Trips that keep you within your home time zone generally won’t affect your circadian rhythms and sleep-wake cycle, if you travel during times when you would otherwise be awake and stick to your regular sleep schedule throughout your time away from home. That means keeping to within 30 minutes of your regular bedtimes and wake times.

Travel that takes you through one or two time zones can have a significant impact on your circadian cycle, cause travel fatigue, and make you vulnerable to symptoms of jet lag. You can minimize circadian disruption and sleep loss, and avoid minor jet lag by:

1. Adjusting your sleep schedule ahead of time.

If you’re flying from Chicago to Boston, start sleeping and waking on Boston time a day or two ahead of stepping on the plane. And on your travel days, be sure to wake up and go to bed at your normal times, according to your destination’s time.

2. Taking short naps. For travel within one or two time zones, short naps of 10 to 20 minutes can reduce travel fatigue without interfering with nighttime sleep. A good general rule? Stick to short naps on short flights and save longer napping (30 to 60 minutes) for longer flights. The same principle applies to traveling by road or rail—napping in the car for an hour or more can leave you wide awake later that night and throw off your sleep schedule for the coming days.

Longer travel, through three or more time zones, poses the most significant challenges to circadian function. For transcontinental and intercontinental trips, you can substantially reduce the severity of jet lag and travel fatigue by:

3. Adjusting your sleep schedule part way to your destination. If you’re flying from Atlanta to Athens—a seven-hour time difference—it’s not realistic to adjust your schedule to Athens’ time before you leave Georgia. But you’ll experience milder jet lag if you shift your schedule partially toward your new time zone. Adjust your bedtime and wake times in 15-minute increments over the week before your departure.

4. Resetting your clock with light and darkness. To speed circadian re-alignment, you need light exposure during the morning hours of your destination time, and you need protection from light during the evening hours. Whether its natural sunlight or artificial light from a handheld device, use light exposure to send “wake-up” messages to your body clock and use darkness to send the message that it’s time to rest, all aligned with your destination time zone. Make sure you travel with an eye mask and book a window seat so you can control the light in your immediate environment.

5. Sleeping and eating on local time.

From the morning of departure onward, put yourself on your destination’s local time. Sleep when locals are sleeping. Eat your meals when locals would be eating theirs. In addition to taking cues from light and darkness, the body takes circadian cues from our eating routines. Giving your body as many of the right cues about its new, temporary schedule will speed the circadian adjustment

6. Avoiding alcohol and caffeine.

It can be tempting to rely on these standbys to help you relax or perk up during a long flight. But both alcohol and caffeine will further disrupt your sleep-wake cycles. Dehydration is a risk when traveling by plane, particularly on long flights, and being dehydrated can interfere with sleep. Stick to water and drink it regularly throughout your trip.

7. Should you take melatonin for jet lag?

I get this question all the time. I generally recommend against introducing new sleep medications, even natural supplements, at the time of travel. Melatonin can be an effective short-term treatment for jet lag, but it’s important to know how to use it correctly. Here’s a discussion of the effectiveness of melatonin for sleep and how it can be used to treat jet lag. It’s important to consult with your physician before using melatonin or any other supplement or medication for sleep.

8. There is an APP for that!

While there are several travel and jet lag applications out there, the one that I personally use and helped develop is called www.timeshifter.com. With only four pieces of information, it will give you a plan two days before you leave, and when you land you are in your destination time zone!

No matter what form of traveling you’re doing, it makes a big difference to start your journey rested—you’ll be less vulnerable to sleep-cycle disruptions if you’ve banked some high-quality sleep ahead of your trip.

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