By Dr. Mercola
Whether you're traveling two hours or 12 hours, your first night of sleep in a new bed is usually not restful. While some of the difficulty you'll experience when you travel is linked to jet lag, there is another factor.
Research published in Current Biology has found that the first night effect (FNE) of disturbed sleep, often regarded as a typical sleep disturbance when sleeping in a bed other than your own, is actually the result of interhemispheric asymmetry.1,2
In other words, one hemisphere of your brain is more vigilant during sleep than the other side in order to monitor your unfamiliar surroundings during sleep. These findings, the result of advanced neuroimaging techniques, explain why your first night at a hotel or your relatives' doesn't always give you the rest you need.
Left Brain, Right Brain
Your brain is the most complex organ in your body, responsible for controlling and monitoring all your systems. Your brain is made up of two halves, commonly called the left and right side. The medical term for "side" is "hemisphere." The right hemisphere of your brain controls the left side of your body, and vice versa.
A typical healthy brain will have approximately 200 billion nerve cells and hundreds of trillions of connections, called synapses.3 Electrical impulses travel over synapses, relaying information.
Only recently has the technology been available to examine those synapses and determine and categorize their function. The number and strength of active synapses fluctuate at different times in your life and with waking and sleeping.4
In general, the left and right hemispheres of your brain process information differently. But to function and communicate, the two sides must work together to see the whole picture and then the details.
Left-brain thinkers are often more analytical and verbal, while right-brain thinkers are more non-verbal and intuitive. Left-brain thinkers are logical and right-brain thinkers are creative.
One side of the brain is not superior over the other, and both are needed to give you a balanced approach to evaluating any given situation.
At one time, sleep was considered an inactive or passive state when both your body and brain were in the "off" position. Today, we know it is during sleep that your brain does most of the housekeeping duties, getting rid of damaging toxins.5
This house cleaning reduces your risk of Alzheimer's and other forms of dementia as you age. During sleep, your brain goes through characteristic cycles of activity, affecting your perception of quality, restful sleep.
The two most distinctive cycles are rapid eye movement (REM) and non-rapid eye movement (NREM) sleep cycles. Many sleep experts believe that you dream more frequently and more vividly during REM sleep.
Your pattern of REM to NREM sleep is distinctive during the night. The average length of time in the first REM/NREM cycle is between 70 and 100 minutes, while the second and later cycles are usually between 90 and 120 minutes.
Scientists have not identified a reason for this specific cycling pattern.6 This normal pattern of sleep can be affected by several different factors, including:
✓ Amount of sleep you had recently
✓ Amount of sunlight you were exposed to during the day
✓ Your internal clock
✓ Your behavior prior to sleep
✓ Being in a different environment
✓ Variety of different chemicals
Your history of sleep in the previous days will have a dramatic effect on your sleep patterns. The more quality, restful sleep you have had recently, the more likely you are to continue that pattern. Frequent disturbances may redistribute your sleep stages, resulting in poor-quality rest.
Yet another factor affecting the quality of your sleep when you travel is jet lag. This is a temporary condition causing fatigue and insomnia as a result of traveling across time zones. Also known as time zone change syndrome or desynchronosis, jet lag is a dysfunction of your body's "biological clock."
Your internal clock, also known as circadian rhythms, is orchestrated by changes in your body temperature, hormone levels, exposure to sunshine and other biological conditions.7
When you travel to another time zone, even just one time zone different from your home zone, your rhythms are slow to adjust and remain on their original internal clock settings for up to several days.
The younger you are, generally the easier it is for your body to adjust to different time zones and for you to attain a restful night's sleep.8
The effect of traveling west to east is more difficult on your body than traveling east to west.9 You might also suffer from other physical and emotional symptoms from the change in time zone and the lack of sleep, including constipation, irritability, dehydration, anxiety and nausea.10
Sleeping in Unfamiliar Places
The function of each side of your brain, how your brain cycles through sleep, and other factors that may impact your lack of restful sleep when you travel all compound the effect sleeping in a different environment has on your brain on your first day of travel.
The study published in Current Biology suggests that humans have something in common with birds and sea mammals. When in a different and strange environment, it appears that half your brain gets less rest than the other half.
In other words, your left hemisphere stands guard over your safety, while the rest of your body and brain rest.11
Investigators asked 35 students from Brown University to take part in this study, hooked up to monitors and sleeping in a sleep lab. As a result of the study, researchers determined there was a consistent imbalance in the sleep cycles of the two different hemispheres of the brain.
Yuka Sasaki, Ph.D., an associate professor of Cognitive, Linguistic and Psychological Sciences at Brown University and one author of the study, says, "It looked like the left hemisphere and the right hemisphere did not show the same degree of sleep."12
The left hemisphere's default mode network appeared to be more vigilant during the first night. This effect disappeared on the second night of the study for each of the participants.
Researchers tested this using sound and EKG measurements. They found the students' brains responded to a noise pitch different than what they had previously been listening to while sleeping.
Investigators also found that students aroused more quickly when a noise was played in their right ear rather than their left. Your right ear is controlled by your left brain and your left ear by your right brain.
These findings supported the idea that humans could rest just one side of their brain during sleep, something never before demonstrated.13
There's an App for That
Mobile applications are useful tools to gather data and for the end user. In 2014, mathematicians from the University of Michigan released an app, called Entrain, to help travelers adjust faster to new time zones and gather data about sleep habits.14 Users enter specific data about themselves and their travel and the app gives them the best way to recover from jet lag.
Mobile app users were asked to give consent to send data back to the researchers.15 The intent was to use the app to gather a large amount of data from travelers and translate the information into a usable means of improving recovery time.
Research was gathered from over 5,000 users in 100 different countries. Investigators found interesting details as it relates to sleep patterns. Women tended to schedule 30 more minutes of sleep each night than men. People who spent more time in the sun would go to sleep earlier and have more restful sleep.
Another unique aspect to the study was the ability to gather data from a large number of people over a short amount of time, using very little resources. Without using a large phone bank of individuals to ask people to recall data, researchers were able to provide help to individuals and get data back in real time.
Do This, Not That
It is a challenge to reduce the effects of both desynchronosis and interhemispheric asymmetry while getting adequate sleep when you travel. While you cannot avoid these effects, you can reduce the impact they have on your ability to rest comfortably when you take several precautions.
Stay hydrated, whether you are flying or driving to your destination. Your brain controls sleep and it functions best when fully hydrated.16 Your brain loses function when you aren't well-hydrated, which impacts your sleep and ability to do specific cognitive functions.
2. Bring Your Own Pillow
Sleeping in a different environment triggers your brain to stay alert. You may get more restful sleep if your head is resting on something that feels and smells familiar.
3. Practice Stress-Reducing Techniques
A high degree of stress will reduce the quantity and quality of your sleep. When you travel, your sleep is already disrupted. Practice stress reduction techniques that you have used at home, such as yoga, stretching, deep breathing or the Emotional Freedom Techniques (EFT).17
4. Keep Out the Light at Night
Your sleep will be deeper and more restful when you don't have light shining in on your face. Bring a sleep mask for those hotel rooms that don't have room-darkening blinds. Practice sleeping in the mask at home so you aren't using it for the first time in an unfamiliar environment.
5. Shut Off Electronics
Blue light from your electronic devices stimulates your brain, and the device will also suppress melatonin you need to sleep well. Turn off your devices at least 90 minutes before you go to bed. Bring a book and book light so you don't have to get up to switch off the light after reading a book to relax before sleeping.
6. Warm Shower, Cool Room
Taking a warm shower can relax you and get you ready for a good night's sleep. However, sleeping in a warm room will be disruptive. Instead, set the thermostat to 70 degrees Fahrenheit or lower.
7. Calming Noise
Bringing things from home can create an environment that helps you to relax. If you enjoy using a recording of white noise or ocean sounds at home, then bring it with you to use at your hotel. Like your pillow from home, it may help your left hemisphere to rest quietly.
Exercise helps to improve your strength and endurance, something you'll need after a night of unrest. However, steer clear of exercise just before sleeping if it keeps you awake, because it is not conducive to a night of quality sleep in some people. In others, however, even late-night exercise has been found to benefit sleep.
9. Avoid Caffeine and Alcohol
Both caffeine and alcohol may disrupt your sleep patterns, leaving you feeling fatigued the next day. Stop drinking caffeinated drinks after 2 p.m. and avoid drinking alcohol while you're traveling. Alcohol is a depressant, making you feel tired enough to sleep, but it will also increase the number of times you awaken during the night so you don't rest peacefully.18
10. Light the Daytime Hours
The more sunshine you are exposed to, the better you sleep. Exposure to sunshine helps regulate your body's secretion of melatonin. Melatonin regulates your sleep cycle. By the same token, sitting under bright lights before you go to sleep disrupts your sleep cycle.19
If you have trouble getting to sleep and staying asleep at home, here are more tips to improve the quality of sleep you get each night.