S5, E4: The Military Secret That Could End Your Jet Lag Suffering

Jet lag doesn’t have to ruin your trip. On this episode of Unpacked, host Aislyn Greene shares her game-changing experience using a jet lag protocol originally developed for Navy SEALs—and digs into the fascinating science of why it works. She speaks with Dr. Jamie Zeitzer, one of Stanford’s leading circadian rhythm researchers, and Andrew Herr, the founder of Flykitt, who transformed military sleep science into a practical travel solution.

Transcript

Aislyn Greene: Jet lag is one of those things that can loom over our trips. I sometimes think of it as, like, this unofficial travel tax. But last year I traveled from San Francisco to Australia, and something was really different. Instead of spending three days in a sleepy, What time is it? kind of fog, I felt normal, I felt alert, and I felt ready to take on the world from pretty much day one. The secret was this kit I found while googling jet lag tips just a few weeks before my flight. It’s an app-based program that was originally developed for Navy Seals and is now available to us mere mortals.

I’m Aislyn Greene, and this week on Unpacked, yes, we are digging into one of travel’s most persistent challenges: jet lag. We’re going to hear from two experts. The first is Dr. Jamie Zeitzer, one of Stanford’s leading circadian rhythm researchers, and he’s going to share what’s really happening inside our bodies when we cross time zones.

We’re also going to hear from Andrew Herr, who turned military sleep science into a game-changing travel product called Flykitt. And just to be very clear, Flykitt has not paid for or sponsored this episode in any way. It was just something that I found and have now tested on three international flights and two domestic flights, and it has worked extraordinarily well each time and finally helped me see that jet lag does not need to be an inevitable part of travel.

Dr. Zeitzer, welcome to Unpacked. Can we start with the basics? What is jet lag?

Dr. Jamie Zeitzer: Sure. I always split jet lag into two parts. There’s one which is a fundamental biological process. You’re travelling over time zones, and the external world that you’re trying to live in does not match the internal circadian clock. So basically you’ve got this internal clock. It’s set around 24 hours. It is telling you to do things that behaviorally you don’t want to do. So it’s telling you to be asleep when you want to be awake, when you want to be awake, when you want to sleep. That’s one part of jet lag.

The other part are things that are biological, but not due to the circadian clock. They’re due to all of the other things that happen when you travel. And this is like having reduced oxygen when you’re flying, eating at unusual times, having increased stress and anxiety—all those other things which basically compound people’s experience of jet lag.

Aislyn: Dr. Zeitzer explained that we actually have multiple clocks in our body: a central clock in the brain and clocks in virtually every organ.

Dr. Zeitzer: You can think of it kind of like an orchestra. So the SCN (suprachiasmatic nucleus) is playing the role of the conductor. You’ve got clocks in the heart, which, again, can function without a conductor, and they sound okay. And you’ve got clocks in the liver, which again can function without a conductor. They sound okay. But if you’re in the audience and there’s no conductor, it doesn’t sound quite right. It’s a little off.

And that’s basically what happens if you don’t have this central circadian clock that these other subordinate clocks can work, but they don’t work well with each other. They’re not well synchronized to each other. So that’s really one of the things that the central clock is doing, is that it’s coordinating all of these other clocks, and it is synchronizing those clocks to the outside world through light exposure.

Aislyn: That’s so interesting. So can you tell me, then, a little bit more about how these different clocks work?

Dr. Zeitzer: The clock itself is around on average 24.2 hours. So it runs a little longer than 24 hours on average. Some people’s are shorter and some people’s longer than that. And if you don’t have regular light exposure . . . and so, for example, if you didn’t have eyes—and there are many people who are blind who have their eyes removed for various reasons—their clock will run without being reset every day. So basically every day they get a little later. And so if you’re blind and don’t have eyes, you move about one time zone per week. So every week your brain moves a time zone while you’re trying to live in the same time zone.

Aislyn: So what do they do?

Dr. Zeitzer: Basically, they just learn to live with going in and out of jet lag for their entire lives. They can take melatonin to help reset their clocks, and that works in some of them, but in others, they generally just have bad sleep all the time.

Aislyn: This really drove home for me how fundamental light exposure is to our internal clocks. Dr. Zeitzer explained the dramatic difference in light intensity between indoor and outdoor environments.

Dr. Zeitzer: When you’re outside California, in San Francisco, say, and it’s a totally foggy day, you’re getting about 10,000 lux of light. If you’re on the peninsula and it’s a nice day, no cloud cover, you’re getting between 50 and 100,000 lux of light. If you’re inside in a really well-lit doctor’s office or in a well-lit bathroom or kitchen, you might be getting around 500 lux of light. So outside, super foggy, dim day in San Francisco is 10,000, super well-lit office 500.

Aislyn: Wow.

Dr. Zeitzer: So you’re talking about orders of magnitude more light outside.

Aislyn: Yeah, and I have a lot of experience with those dim, foggy days. So even knowing that we’re getting that much light on the foggiest of foggy days is really interesting. And light was actually a really big part of Flykitt. So why do you think it worked so well for me?

Dr. Zeitzer: Sure. So there are a couple things kind of going on. The basic, how the clock shifts to a new time zone has been well understood for many years. Different people have different sensitivities to light, but basically there are various kinds of apps out there based on fairly well-described mathematical models you can use to help you adjust using light to get you to a new time zone. So that’s part one. Part two is if you adjust your food intake in the right way, you can adjust your gut clock faster than you can adjust your central clock. And that helps in kind of two ways. One is that then you’re not feeling so icky all day because your nutritional needs are getting met in the way that your body is expecting them to get met. And also, you’re not disrupting your sleep because you’re not waking up hungry because your brain’s not saying, Oh, it’s dinner time, even though it’s four o’clock in the morning.

Aislyn: What about melatonin? Because that is part of the Flykittt protocol. And travelers, you know often use it.

Dr. Zeitzer: Melatonin can help shift you. It’s got a small effect. It’s about one-tenth the strength of light when you’re looking at, like, how much does melatonin shift you. Melatonin, however, can help you avoid light, which is part of shifting, is getting light at the right time and also avoiding light at other times. So melatonin is an okay hypnotic medication as well. So basically it helps you sleep, but it really only helps you sleep during the daytime. So melatonin at night doesn’t do much. Basically, the parts of the brain that are sensitive to melatonin are not sensitive to it at night. And so if you take a look at the double-blind, placebo-controlled studies of melatonin given at night, it gets you about an extra 10 minutes of sleep. If you look at the open-label studies where people are given melatonin, they know they’re taking melatonin. They get about a half hour of sleep.

Aislyn: Dr. Zeitzer also stressed something I hadn’t really considered, which is the role of psychology and expectation.

Dr. Zeitzer: A good part of jet lag is expectation bias, which is if you think, Hey, I’m going to get there, I’m not going to have jet lag, I’m going to be, I’m going to sleep fine. That’s going to help. If you travel and you’re thinking, Oh my God, this is the worst. It’s going to be terrible. I’m not going to sleep. Amazingly, you don’t sleep.

Aislyn: Yeah, totally.

Dr. Zeitzer: You know, so even if it’s not a positive bias, it’s getting rid of that negative bias. Which is crucial.

Aislyn: Because, yeah, like I’m not a great sleeper. And so times where I’ve gone through periods of more insomnia, that fear of, like, not being able to sleep . . .

Dr. Zeitzer: If you’re a good sleeper to begin with, they have less trouble with jet lag because they just have fewer barriers. If you’re a bad sleeper to begin with and then you’re jet traveling, well, welcome. Welcome to life with the rest of us. Because it’s then terrible. Because not only do you have all your bad habits, then you also have this new circadian thing that’s helping you stay awake, too. And you’re in an unusual place, and there’s anxiety there, and you’re eating weird foods.

Aislyn: These insights helped me understand that jet lag isn’t just about time zones. It’s about multiple biological systems trying their very best to sync up in a new environment. But how exactly do you manipulate these systems effectively? After the break, that’s where Flykitt’s Andrew Herr comes in.

We’re back. And joining us is Flykitt’s Andrew Herr, whose background is fascinating. It’s this unique blend of health physics, immunology, and national security policy, and that led him to work with Navy Seals and fighter pilots.

So, Andrew, welcome to Unpacked. I would love to just start at the beginning. How did Flykitt come about?

Andrew Herr: So actually it was working with clients who were having personal, terrible experiences with jet lag. You know, I’d spent seven years working with the military and worked on all kinds of performance issues, including sleep and circadian questions. And then one day this client came to me. He was a business executive flying from the East Coast. He was going to Korea regularly to close business deals: land at 4 p.m., there’s a big dinner that night, and the Korean side wanted to negotiate at 7 a.m. the next morning. And he’s like, We’re getting—pardon my French—effing killed here. Like, they’re using jet lag as a negotiating tool. And so he’s like, What can I do?

Aislyn: Andrew took everything he’d learned working with those Navy Seals and those fighter pilots and created a protocol in a Microsoft Word document. It was the very early iteration of Flykitt.

Andrew: I sort of took all of this knowledge that I’d built working with the military side, working with individual executives, and had one of those moments where I just sort of like put it all together, all at once, taking these insights from work I’ve done with this Navy Seal community. I learned working with them that pressure changes in diving can cause inflammation, and then tracked this to flight, and then tested it with some fighter pilots who were having some mental brain fog issues after they flew, tested that hypothesis, and it worked with them. You know, put that kind of approach together with all these light and meal timing and supplements that could shift your circadian rhythm, blocking this inflammation. Also, knowing that not sleeping well on a plane and other things gives you inflammation, just put it all together and typed out a, at this time, Do this at this time, like, carried a box of supplement bottles to his office, oh my God, I think I hand-delivered it, if I remember correctly, and he emailed me from Seoul, Korea, I guess a couple days later, and said, Andrew, I just slept eight hours my first night. Like, what did you do?

Aislyn: That’s amazing. I think anyone listening who has done a similar trip understands that an eight-hour sleep is bonkers. So help us understand, How does it work? Can you walk us through the steps?

Andrew: The basic framework is you’re a busy person. I’m not going to ask you to do anything before the morning you leave. Starting the morning you’re going to leave, the app is going to recommend you actions first that are going to prepare you to block that flight-induced inflammation and then kind of keep your inflammation low and healthy throughout your trip. The second thing we’re going to do is we’re going to decide what time is ideal to wake up based on your circadian shift you need. So, but, it’s not just the shift you need because it also is, When do I need you to sleep? Because you can’t sleep on a layover or when you get to the airport. That’s just not feasible. There’s not a bench for you to sleep in, in the airport.

So we’re gonna, if I need you to go to bed and sleep relatively early relative to your home. Sleep time on the plane, I might have you wake up earlier. I’m managing you to try to feel as good as possible throughout your trip while also being as ready as possible to sleep when I want you to sleep. There’s a balance there, because if I give you tons of energy and it’s 10 p.m. at your destination, you can’t fall asleep till 3 a.m., you’re going to feel horrible the next day. Yeah. So you need to feel tired at the right time.

Aislyn: Yeah, that makes sense that you have the app, then. And so what is in the Flykitt box? What are those specific components?

Andrew: The Flykitt pack comes with all the different supplements you need. There’s five different ones in there. And the app will just tell you, you know, Take one of the advance or sustain or protect at the different times. And then I’m going to help you prepare for sleep, which might include supplements or definitely includes blue-light blocking glasses that come in your kit. And those are going to help tell your brain it’s getting to be nighttime because they block the blue frequency light that’s sort of a signal to your brain that it’s daytime. And they tend to help people calm down a little bit for that and other reasons as well. It’s less stimulation. And then you’re going to sleep. Usually during your flights, you’re going to sleep on the way toward your destination, but not too much and not too little.

Aislyn: Yeah. So how do you determine how much someone should sleep on the plane, then?

Andrew: That’s a really neat trick of, like, What’s the amount that allows you not to feel terrible? But that’s also going to allow you to go to bed that night. And the answer is we can give you a little bit less sleep than you could normally get, because the first-order negative effect of not sleeping is inflammation. And we’re managing that already. And by the way, that’s why jet lag can be so bad. Because if you don’t sleep and the flight-induced inflammation. And so we’re kind of managing your sleep, managing your, how awake you feel. Then you’re going to wake up. And typically it depends on the plan, obviously. But typically we’re going to hit you with what we call a circadian reset. That’s this drink you’re going to miss, where you’re going to combine the right amount of coffee that we predosed with this methylated B vitamin sugar mix that’s going to give, it’s going to suppress melatonin levels in your body to make you more awake. And then it’s going to give you a little insulin hit that helps reset your circadian rhythm in your liver and your gut, kind of not just in your brain, but in the rest of your body. And then that’s going to power you through the rest of the day. And we’re going to keep managing the inflammation, keep managing circadian with our goal of landing you nicely in bed that night. You sleep that full night. And you really are just on destination from your first night.

Aislyn: Yeah. And that’s what I experienced on my Australia trip. So what about food, then? Because when I, on that Australia trip, the program was actually pretty aligned with when they were serving meals on the plane. But I know that’s not always true.

Andrew: Yeah. So the eating is really powerful because basically the worst thing you can do is not have enough sleep and not give fuel to your brain and body. So we want you to be eating, but we, your body, when it’s traveling and having stress or inflammation or not sleeping as well, doesn’t handle carbs as well. And so we want to sort of, you know, you don’t have to eat no carbs, but we want to recommend a higher-protein, lower-carb diet because it’s a little bit more aligned with your physiology during that time.

And then that also allows us, when we give you that little sugar hit, it’s not a crazy amount. It’s only 13.5 grams, but that then sort of saves that little insulin blip for the time when I want to reset your circadian rhythm to the morning time frame. So it will sometimes work out that the meals are timed with the plane flight, because usually you’re going to, it’s going to make sense to sleep kind of more in the middle of the flight, but we don’t currently optimize for that in the plan, just because sometimes the meal times in planes would be really kind of off.

Aislyn: Got it. Okay. In general, what kind of response have you seen from travelers, and what kind of results are you seeing?

Andrew: I mean, in our, in our look back at the data we’re looking at, about 93 percent of people get a tremendous benefit from this. And we just ran a kind of pilot recently with Inter Miami, the professional soccer team, and they saw a 94 percent reduction in symptoms for people who use Flykitt, and their players use Flykitt. So we’re seeing really huge effects.

So what about the other 7 percent of people? And my answer is nothing works for everyone, and anyone who claims that any medicine or supplement or workout regime works for everyone is lying to you or wrong. But we’ve looked at this and tried to figure out, Is there a demographic? Is there an age, sex? We actually don’t see a pattern. And obviously, I want to, I want it to work for everyone, but trying to figure it out for those other 7 percent, honestly, is probably going to be so hard that I’d rather just give their money back. And that’s what we do. We have a money-back guarantee. If it doesn’t work for you, we’ll just give your money back because this is there to help people. And if it didn’t help you, then, then we shouldn’t get paid.

Aislyn: Okay. All right. Well, you heard it here. Um, I know you have some big things on the horizon, including going beyond those international trips. Can you tell us a little bit more about what’s to come?

Andrew: The other big thing on a road map coming soon is—you use Flykitt. It’s designed for these big international trips. We’re going to be launching a Flykitt domestic product here that is designed to help you feel great on shorter flights because you still get that inflammation piece, even if there’s, you know, maybe a smaller circadian component. Certainly, you know, West-East Coast, East-West Coast, there’s a little more circadian. But even just going, you know, one time zone or no time zones, but a few hours north, south, you’re still, you know, you don’t feel great when you get off a plane, and people will say it’s the dry air and other things, but it’s really this flight-induced inflammation from the pressure change and the low-oxygen environment.

So, in January, the Delta CEO announced a partnership this year with Flykitt. So I can’t say more about that at this time, but obviously that’s something that would be quite exciting. And then we’ve started, you know, our first kind of bigger military partnerships to—you know, some of this research came out of the military. And so it only feels right to get this technology back in the hands of the people who in some respects need it the most and are traveling all over the world. And our mission is to help people so that they can do more for themselves, their family, their community. And so having the opportunity to talk about it is really valuable. So thank you so much.

Aislyn: And that is it for this episode of Unpacked by Afar. Again, this was not a sponsored episode, and this is not an affiliate link. But if you’d like to try it, if our listeners can get 10 percent off with the promo code AFAR10. That’s AFAR10, and I’ve included that in the show notes.

I’m Aislyn Greene. Thank you so much for joining us. If you enjoyed this deep dive into the science of jet lag, subscribe to Unpacked wherever you get your podcasts, and be sure to share it with a fellow traveler who is tired of being tired.

Ready for more unpacking? Visit Afar.com and be sure to follow us on Instagram and TikTok. We’re @AfarMedia. If you enjoyed today’s exploration, I hope you’ll come back for more great stories. Subscribing always makes that easy. And be sure to rate and review the show on your favorite podcast platforms. It helps other travelers find it.

And if you want to ask a question or suggest a topic for coverage, you can leave us a voicemail at the link in the show notes, or email us at [email protected].

This has been Unpacked, a production of Afar Media. The podcast is produced by Aislyn Greene and Nikki Galteland. Music composition by Chris Colin. And remember, the travel world is complicated. We’re here to help you unpack it.