How To Beat Jet-lag

What science and being a full-time nomadic parent has taught me.

A few years ago, after a 13 hour flight from San Francisco to Berlin, my husband and I met up with some friends for dinner. I was exhausted, so I went back to our Airbnb ahead of him and fell asleep. Hard. So hard that I slept through multiple phone calls, texts and him ringing one of those extremely loud german doorbells. Not only did he have to sleep at a friends place - he also had to find breakfast and lunch on his own the next day because I soundly slept well into the afternoon.

I can be such a snob about things like luggage and airport etiquette but then I'd totally spend the first week in a new city sleeping til noon like a total amateur.

But I have a toddler now. And since sleeping through the night is still rare, let alone "sleeping in" or "catching up on sleep," jet-lag, like hangovers, are expensive. So after a summer stacked with international flights I finally did the research and experimenting to figure out exactly how to actually beat jet-lag. I went down a rabbit hole of research papers and learned from the best; professional bio-hackers like Tim Ferris, olympic athletes and flight crews. I came up with a plan. Then I tested and revised. A lot. This article, the result of years of trial and error, is my gift to you.

How This Article Is Different

There's a lot of pop science on jet-lag. But most of it has two big problems and today I'm going to fix those for you. First, most say things like "stay hydrated" and "get plenty exercise," without explaining WHY they are important SPECIFICALLY for jet-lag. You could replace the title on almost anything written on the subject with "Top 10 List of Generic Healthy Habits." Two, most articles give equal weight to all their tips (probably even adding in a couple with very little science backing just to get to an even "top 10"). And three, most articles don't get specific enough to create an actionable plan from it. "Stay hydrated" is not a SMART goal, people. "Drink 8 ounces per hour" is better. "Calculate total water consumption by multiplying 8 ounces of water times the number of hours you are in the air, then drink 30% of it before the flight, 20% before you nap (to avoid sleep disruption) and 50% after you wake."Now that's more like it.

To help you get the most of my months of research I'm going to do the following:

Explain the basic biology behind jet-lag and give solutions that address the root causes directly. I won’t just tell you to drink water, I’ll explain exactly what part of flying causes dehydration, how bad it is, why it contributes to feeling like crap and how much you actually need to drink and when.
I'll only talk about flying west to east when I talk about schedules and time changes, because that's where you lose time. Flying the opposite direction is generally easier on your body and it's not worth confusing you by creating multiple sets of schedules depending on which direction you fly.

The Biology Behind Jet-Lag

Websters's dictionary defines Jet-Lag as... Just kidding. But, don't skip this part. You gotta know what's going on under the hood before any of this will be helpful because there's 6 completely distinct, fun-filled reasons you can feel shitty after a flight :) And each requires its own strategy.

Since we're on it, a quick note on vocabulary: jet-lag is technically only caused by time zone changes, everything else is travel fatigue. I'm going to talk about both but just use jet-lag for simplicity. I'm oversimplifying, yes, BUT that means you can use these tips every time you fly, not when you change time zones. So in order of impact, here are the five things that cause jet-lag:

Misaligned Hormone Production Timing. Every organ in your body operates on a 24 hour cycle. Those rhythms are regulated by different hormones being released at different times of day (That's the Endocrine System if you wanna dig into this more.) Without oversimplifying too much, hormones like melatonin makes you sleepy at night, cortisol makes you more alert in the morning, ghrelin makes you hungry at certain times, secretin kicks your digestive system into gear, and lower levels of thyroid hormones decrease your body temperature in the evening. Even your blood pressure has a daily rhythm. Changing time zones isn't just destructive to your sleep, it messes with a zillion other processes. That means until your internal body clock catches up with the new schedule, you can experience everything from gastrointestinal issues (by eating when the body isn't ready to digest food), headaches, difficulty emotionally regulating and poor concentration, the list goes on. This misalignment has the biggest impact on jet-lag and we'll spend the most time in the next section on how to hack it.
Lack Of Sleep And Time. Flying East means you lose time (versus flying West where you gain time). If your east-bound redeye lands at 8am, whatever sleep you got on the plane (probably only a few hours) is what you have to get you through the entire next day. For most people, it means they're starting off in a sleep deficit. To compound things, lost time means less time for your body to adjust to the new clock. Plain and simple sleep deprivation.
Dehydration. You already know flying dehydrates you. But do you know how bad it really is? It's pretty bad. It’s more difficult for air to hold moisture at higher altitudes, so the air is dryer. How much? Your house is probably anywhere around 30-50% humidity depending on where you live. One of the most arid places on earth, the Atacama Desert, averages around 17%. The Boeing 787, which advertises high cabin humidity as a selling point is about 15%. Most other airlines are much lower, just above 0%. Pretty bad right? Theoretically airlines could add humidifiers, like you would in your home, but that would require bringing a lot of extra water, which equals extra weight, which increases fuel costs etc.
Poor Blood Circulation And Oxygen Flow: Because the cabin pressure is slightly lower than at sea level, the air in the cabin is thinner (typically as thin as on a 7000ft mountain), which means less oxygen coming in for every breath you take. In addition to less oxygen overall, sitting for extended periods of time causes your blood to disproportionately pool in your legs and feet, which means your body is less efficient at circulating the decreased oxygen it does have. Your brain gets less oxygen than usual, which is the primary reason you feel generally crappy, but all your other cells are also getting less oxygen, which, like bad nutrition, compounds quickly and has complicated impact.
Suppressed Immune System: Physical stressors like dehydration, sleep loss and low oxygen can weaken your immune system. Exactly how that works and how much it will impact you is a bit hand-wavy. But a circadian rhythm disruption does have a direct immune system response. When the body receives light signals when it's not used to, it will actually stop producing T-cells, which is part of your immune system response.

How To Beat Jet-Lag: A Breakdown by Root Cause

So here's how to fix all your problems.

How To Realign Your Circadian Rhythm

The most important thing you can do to minimize jet-lag is to reset your internal clock as fast as humanly possible. Devoid of environmental stimuli, your brain would theoretically stay in the old time zone forever, but once you land and start giving it hints that it's in a new time zone, (like daylight, food and temperature) it will begin to adjust, albeit slowly. Roughly one day for every time zone (though there's debate on just how linear that math is). So let's talk about what to hack and how to hack it fast.

#1: Fasting. If you don't have a kid, you can kind of ignore every other tip related to bio rhythms. It's a game-changer in terms of resetting your body clock. Why? Turns out, food availability wields WAY more influence over our sleep cycles than light. Whyyy? Because food is so crucial to survival, the body can override the influence of light and dark to match the availability of food. And we can leverage this food-centric body clock power through fasting. If sunlight is like slowly rewinding a watch dial, fasting is like pulling the crown out and shoving it back in for an immediate reset. The science says so and my anecdotal experience agrees.

What you do is: a 16 hour fast that ends at either your destination's breakfast or dinner time (depending on when you land). What that usually means for 10+ hour flights is you just don't eat while you're in commute. An example for a 12pm flight from San Francisco to Amsterdam: Wake up and eat a large breakfast sometime around 8am, head to the airport, skip the crappy plane food, land at 8am local time and grab a big celebratory breakfast at 9am (16 hours from your last meal.)

Effectiveness: If you want results, this is the best possible strategy. The downside is that it is HARD, and not actually possible for everyone, like kids, that's why I'm not just ending this topic here. But, if you wanna solve most of your jet lag problems in with one strategy, this is it.

#2: Light

Second to food, light and darkness is how your body sets its internal clock. So be crazy strict for 24 hours about getting light at the right times. If you land in the morning, spend as much time as possible outside. Then once the sun sets be super strict about keeping the lights low indoors. Fun fact: the light receptors in your eyes are more sensitive to light coming from above, so even using a table lamp instead of an overhead light in the evenings has a big impact. Also fun life tip- being outside during sunset is a phenomenal way to get your body to start doing all of its internal night routine things. When the time zones allow for it, I love sitting outside with a glass of wine during sunset (whether I can see it or not) as a ritual to get my body into "evening mode."

#3: Help from Chemicals:

The body clock is really just a schedule of hormone releases so if you're a supplement junkie, like me, the pharmaceutical industry has many shortcuts. The obvious first choice is melatonin. You can take it on the flight around 8pm local/destination time to get a jump start, plus it will help you sleep on the flight. For a more natural option, add some carbs and/or turkey with dinner after you land. Both kick up serotonin production, which is a precursor to melatonin. Lastly, caffeine keeps you awake by actively blocking the brain's adenosine receptors, which overrides the tiredness feeling we have from lack of sleep, thus you can use it to realign the wake/sleep cycle. Just nix it after 3pm (caffeine has a crazy long half life of around 6 hours) or you risk messing with your sleep.

#4: Get Ahead:

I hate this tip, but I'll include it for completeness. If... you're fortunate enough to have foresight, a flexible schedule, personal freedom, and willpower, you can start adjusting your sleep schedule in the days leading up to your flight. And if you want to go for extra credit, you can start doing some of the things mentioned above before you leave; changing your light exposure, supplementing with melatonin etc. At the very least however, you should practice what I call "Fiona's Rule of Air Travel," coined by my dearest Aussie pal whose many, many Melbourne-to-San Francisco-and-back trips has made her an expert in jet-lag. Fiona ruthlessly adopts the schedules and routines of her destination time the moment she boards an airplane. If her flight leaves at 11pm Melbourne time (6am San Francisco local time), she'll bring a scone, order a cup of coffee and start checking her emails while the guy next to her is putting on a sleep mask. Once while we were having dinner I asked her, "wow aren't you tired, what time is it in Melbourne?" and as my husband looked at his phone to do the math she covered her ears and said "No No No! Don't tell me!" She's kind of an adorable stickler about it. And she also never seems to get jet lag. Fun fact- Flight crews operate on Fiona's Rule of Air Travel by publishing all of their on-board shift schedules in local time.

How To Catch Up On Sleep

Even if you're one of those obnoxious people who sleep well on planes, you're going to have a bit of a sleep deficit to make up. You can either make it up the night before you leave, on the plane, or after you land. How many hours to put in each bucket should depend on practicality and convenience, but the goal should be to get 6-8 hours total sleep the night you travel. Here's how I think about it. "After you land"sleep (a la sleeping til noon or taking long naps during the first few days) is a last resort. It just slows down your body clock reset and isn't really possible with young kids. Sleeping extra before you leave is a good buffer, but you're not going to get 8 extra hours of sleep in before you leave. Sleeping on the plane is the most ideal, but most difficult in practice. The strategy that's worked for me is to is to take an Ambien the night before a flight and aim to get 10 hours. Then, my husband and I sleep in 4 hour shifts on the plane. After we land, we make up the last 2 hours by going to bed early the first night. However you do it, the best advice I have is to at least have a plan, otherwise your body will decide for you – usually by crashing

How to Hydrate

This section is essentially a best practices for hydration, airplane edition. You need to drink 8 ounces for every hour you're in the air. And that's not debatable like the whole "you need to drink 8 glasses of water ever day." That's really how much water you need to physically consume to avoid dehydration. So how on earth do you practically make that happen? First, pre-hydrate.One of my hacks is to fill my water bottle before I leave for the airport, that way I'm forced to finish it before I go through security.

Oh and I have good news about the "avoid alcohol because it dehydrates you" advice that's pervasive on this topic. I love drinking on flights. That's not the news. Red wine on airplanes is pretty much a requirement for flying with a toddler. So I dug in. I read the studies. I wanted to know just how much of a diuretic is alcohol. Like, am I completely fucked if I have a glass of wine or does that mean I just need to drink some extra water? Or what? What's the science say? Turns out, unless you're pounding shots, you're probably fine. There's a study they did that tested the diuretic effects of different types of alcohols on elderly men and found that weaker drinks (like wine or beer) are safe in terms of hydration in moderation, of course. And although the diuretic effect increases with the alcohol content, the effect is relatively small and short-lived. So if you decide to simply ignore my advice on fasting, enjoy the free drinks. You're welcome.

How to Increase Oxygen Intake & Circulation

Breathe more! Just kidding. There are SO many different tactics on increasing circulation and the comparative effectiveness gets fuzzy so I think the most helpful way to discuss these is to rank them by amount of effort required. Then you decide what's easiest for you.

Take an Aspirin before the flight. Aspirin temporarily thins your blood making circulation a bit easier and reducing the risk of blood clots (which i am weirdly paranoid about while flying).
Take Magnesium. Magnesium is a miracle supplement when it comes to helping blood vessels relax and most people don't get enough from their diet alone anyway, so yay supplements.
Wear compression socks. The way these work is by making it harder for blood to reach your feet by sheer physical squeezing force. Thus reducing the amount of blood that gets stuck there. Professional marathon runners ALL use these so I feel like there must be something to it.
Do inverted yoga poses. Essentially, get your feet above your head to get everything moving again. I, personally, swear by this. I like to prop my feet up against a wall near the baggage claim carousel while I'm waiting for our luggage. It seems like it would look strange but everyone knows what you're doing. I also do it for about half an hour in bed before going to sleep that night.
Massage. Takes some planning to fit this in after a day of travel but well worth the effort.
Exercise. In addition to increasing blood flow, everyone on the internet swears exercise is a way to reset your sleep wake cycles but there's no studies that show a direct link to your circadian rhythm. There is speculation that increased body temperature from exercise can impact it, but the science-backed part is all related to getting oxygen to your muscles. That said, exercising in sunlight feels synergistic in fighting jet-lag.
Saunas and cold plunges. Nothin gets the blood flowing like cooooold water. The least convenient tip on this list, but one of my favorites, especially when traveling to Europe where bathhouses are larger part of the culture.

So that's my magnum opus on jet-lag after a summer of research and practice. If you're like me and want to put all this disparate information into an actionable plan, stay tuned for my next post where I'll take you through my End-To-End Anti-Jet-Lag Travel Routine. And if you take nothing else from this article, at least try to be a little kinder to yourself when flying. It's way more stressful on the body than you may have considered before. Luckily, the human body is incredible and will correct itself eventually.

What jet-lag tips did I miss in my research? Got any favorites? Leave a comment below!

References:

How To Beat Jet-lag

How This Article Is Different

The Biology Behind Jet-Lag

How To Beat Jet-Lag: A Breakdown by Root Cause

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