Question: Why do we get jet lag when we fly to a different time zone?
It goes without saying that while traveling is generally rewarding and exciting, it is exhausting. Ever notice how when we get to a place, we are so excited to hit the ground running only to crash hard later that day?
And with the holiday season fast approaching, airports will be buzzing with reunited families, friends and folks on holiday vacation. Many people travel out of their normal element during this season and just feel kinda out of whack for a while. Could this be the explanation for those crazy relatives we all have?
Or maybe they’re just crazy.
But really, traveling to different time zones can be taxing on the mind and body, even with just a one-hour time zone change. We get that out-of-whack feeling known as jet lag.
Jet lag is defined as a “temporary disorder that causes fatigue, insomnia, and other symptoms as a result of air travel across time zones.” It disrupts our circadian rhythm sleep. You know, the cycles of deep and non-deep sleep, or REM (resting eye movement) and non-REM sleep.
So let’s back up a bit.
Circadian rhythm: Not a head-swaying bongo drum beat, but our24-hour internal clock that cycles through our alertness and sleepiness in intervals, or our sleep/wake cycle. This cycle is how our bodies come to be sleepy during the nighttime and wakeful during the day.
This cycle is influenced by many factors; for example, instead of solely relying on timing to induce your circadian rhythm cycles, it’s also influenced by differences in light. Dips in our energy cycle happen about twice a day and vary from person to person (which can help explain “early birds” versus “night owls”).
These swings in energy and alertness are usually pretty gradual and not too noticeable — that is, when we’re adjusted to a regular sleep schedule. However, when we experience jet lag, this pattern becomes quickly misaligned with the day-night cycle and can cause confusion in the body’s release of melatonin, the hormone our body produces that makes you sleepy.
Because the body’s circadian rhythm can be easily disrupted and is partially influenced by light, we see all sorts of issues related to this cycle with people working night shift jobs and other shift work. Specifically,Shift Work Sleep Disorder (SWSD) has become quite the hot topic in sleep research at the moment and is primarily due to the circadian rhythm being out of whack.
But as for travel, interestingly, a “general” finding is that for every one hour of time zone change encountered in travel, it takes about one day to adjust. So even going on that European trip for a week could wreak havoc on your internal clock for the entire time you’re there.
Like that would ever stop me from going.
The amount of jet lag also varies when we consider the direction we are traveling. For example, when we travel forward through time zones, you are actually setting your circadian clock backwards. If you think about flying from California to New York, you are traveling three hours ahead but are trying to fall asleep three hours before you usually do.
Andresearchers found it takes longer to “reset” your circadian clock when traveling east rather than west. This is because it is generally easier for people to stay awake longer (especially when exposed to bright light) than to sleep way before bedtime.
Now, there are tons of those “lists” online telling us how to minimize jet lag, with tips like “get a good night’s sleep the night before” (like that ever happens), or “gradually adjust your sleep patterns before you leave” (again, really?) or “avoid arriving to your destination at night” (okay, this I can understand). But is it really that simple?
The answer is no, and it’s the disruption of our circadian rhythm where we find ourselves in trouble. Jet lag may not sound like that big of a problem when it happens once in a while, but the underlying issue, sleeplessness, is becoming an increasingly common occurrence with some pretty severe consequences.
The National Sleep Foundation recommends, on average,eight hours of restful sleep per night for the average young adult.
Sure … I can do that.
Okay, who am I kidding?
And sleeplessness happens on six-or-fewer hours of sleep.
Now that sounds more like me.
Oftentimes we feel superhuman and believe we can survive and thrive on five or six hours of sleep. I mean basically everyone in college, amiright?
But asDr. Matthew Walker, director of the Center for Human Sleep Science at UC Berkeley, explains, if humans were evolutionarily able to thrive on five to six hours of sleep a night, we would have conditioned ourselves to do that a long, long time ago.
Because if you think about human survival millions of years ago, those extra waking hours could be put to good use: finding food, shelter, mates, etc. But instead we use it for sleep, which indicates we need that certain sweet spot of sleep to be our best selves. Those eight hours contain some formula for success.
Even small changes to our normal circadian rhythm can wreak havoc on our bodies.
This can be seen in the most widespread sleep “study” of all: Daylight savings time.Researchers found a 24% increase in heart attacks from the one-hour “spring forward” of the clocks in the spring season! That is some seriously grim news. They additionally saw a 21% decrease in heart attacks when we “fall back” an hour in the autumn.
It’s wild to think about how just one measly hour is not a measly hour at all, but something that truly has long-term effects on us.
I treat an hour like nothing really. An hour less of sleep here and there because of simple, everyday things like socializing, studying, movie-watching or just when I can’t fall asleep, seems like nothing. I never realized how just one day of sleeplessness can have compounded effects.
Now this is by no means a death sentence, especially when it comes to getting jet lag. There are some scientifically explained variations in jet lag, as well as some science-backed methods to reduce and alleviate symptoms of jet lag (that don’t include sleeping or refraining from alcohol).
If you have the flexibility, consider which direction you are traveling when picking destinations. Additionally,melatonin or caffeine could be used to help minimize the symptoms of jet lag and aid in the resetting of the circadian clock (best excuse for that expensive latte, right?).
But all in all, jet lag is pretty unavoidable these days with globalization, and it certainly won’t hold back most people from traveling. However, just being aware of the causes and symptoms of jet lag, how it affects our bodies and just how important and fragile restful sleep is, can be effective tools when trying to manage our sleep schedules.
It’ll honestly make me think twice when wanting to watch another late-night episode of “The Great British Bake Off,” but, I’ll probably watch it anyway. I mean, how can you say no to watching wholesome, quirky British bakers make hot cross buns and mince pies?
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