The last time I travelled to a place in a different time zone (Hong Kong a few years ago), jet lag was not kind to me. However, during my trip to recent trip to Shanghai, these problems were much improved. In the years between the two trips, I learned some things about sleep and circadian rhythms, and I believe that applying this information is the main reason why I beat jet lag this time instead of the other way around.
Therefore, I thought it would be a good idea to share these tricks so that if you’re travelling to some distant location for a vacation or business trip, you can be better prepared and adapt more quickly to the time zone of your new destination.
Although they are focused on jet lag, in reality, many of these tricks are useful in everyday life if you have sleep problems or simply want to sleep better, so I can assure you that this information will be useful not only for your trip but also in the time following it too, hopefully for the rest of your life.
Light Exposure
On the majority of matters involving circadian rhythm, light exposure will be the biggest player to manipulate, jet lag being no exception. Since I’ve written about the role of light in sleep and circadian rhythm already, I will leave out the details and get straight to the practicalities (though if you are interested, do check out the linked article).
The detection of photons in your eyes and UV radiation on your skin send signals to your brain that it is time to be awake. Knowing this, we can use light as a tool to manipulate our sleep/wake cycle. Probably the most useful application of this would be the case in which you have to wake up in the morning in your new destination, despite your body clock being set a few hours behind and expecting to be in sleep mode. In this scenario, be sure to get as much light as possible in your environment, and ideally get outside in the sun so you also get UV exposure.
Use the same approach if you’ve travelled west, and your body thinks is almost bedtime, yet it’s the middle of the afternoon. In this case, maintain adequate light exposure and avoid dimly lit areas to tell your body that it’s time to be awake.
Conversely, if you’ve travelled east and need to be preparing for sleep despite your body thinking it’s the early afternoon, give yourself the best possible chance by setting a realistic sleep time (i.e., not too early) and making your environment dark in the couple of hours preceding that. Exposing yourself to light in that time will only dampen your chances of sleeping on time and therefore adjusting appropriately. Give yourself the best possible chance of doing this by using a comfortable sleep mask, so that even if you cannot control the environment, you can control your own exposure.
Tactical Napping
Naps are wonderful tools for managing fatigue but have to be used correctly, otherwise, they could exacerbate issues related to jet lag. When limited to approximately 20–30 minutes (and not within ~5h of your evening bedtime), naps lead to a quick dissipation of fatigue without entering a deeper sleep cycle and interfering with evening sleep. This means that tactically napping throughout the day can be a fantastic way to manage fatigue until you sleep at night, and since these naps won’t interfere with your evening sleep, you will probably still sleep fine on the night, thus helping to adjust your body clock more quickly.
Furthermore, we combine these naps with the natural ~3h energy cycles that our bodies tend to demonstrate across the day. Even under normal, well-rested circumstances, there appears to be a natural ebb and flow of energy availability in the body, characterized by peaks and troughs that are approximately 1.5h apart. You might not always notice these unless you pay attention to them, but during times of sleep disruption, they will be more pronounced. Thus, if possible, plan your naps in the troughs of these mini-cycles. In this way, you will fall asleep more easily, rest better, and free up the time when you have more energy to enjoy your travels or be productive
When used incorrectly, napping could get you in more trouble. For example, if you have travelled eastwards and you nap too long, you could reinforce the time of your origin rather than your destination in the body, meaning when it’s time to sleep on the night you might be unable to, meaning that overall, you may get less sleep, and the quality of each nap could be lower as well.
Food
Food has a bidirectional relationship with circadian rhythm, meaning not only does circadian rhythm tell you when your body is primed for food, but food also influences your circadian rhythm and tells your body whether it should be awake or not. This means we can use food to our advantage to help us establish our desired sleep/wake schedule more quickly.
The concept underpinning this approach is that our bodies are designed to eat during the day and fast during the night. Our body facilitates this through various physiological changes that enable us to better handle food during the daytime hours, and then prioritizes other processes during the night. This is reflected in the fact that consumption of more calories late in the night is associated with poorer metabolic health outcomes and weight gain.
Consequently, if food enters our system, the physiological processes required to deal with this mean that processes involved in initiating sleep are suppressed, and thus the body will think it’s time to be awake. This is reflected in the fact that sleep quality suffers following larger meals before going to sleep.
The approach would be to eat in line with your destination time zone rather than the one you’re coming from. Let’s say you’re coming from east to west and, whilst your body might feel like it’s time for sleep, your destination time zone is the afternoon and therefore too early to hit the hay. In this case, it might be helpful to eat meals like you normally would — in this case a late lunch and then dinner a few hours later — before going to bed at a reasonable time.
Alternatively, if you’re going west, you’d limit food intake when arriving at your destination in an attempt to use the absence of food to tell your body that this is the time it should be going to sleep. Obviously, this could mean longer periods without food, so if it’s too difficult to completely abstain from eating then consider light snacks, eating as little as possible.
Exercise
Similar to food described above, exercise can also be used to anchor circadian rhythm and tell the body whether it’s time to be awake or not. Obviously, if you’re exercising your body is not going to be prepared for sleep since the physiological processes involved in these actions oppose each another.
That is, when we exercise our breathing shortens, our heart rate is elevated, the sympathetic nervous system is activated, and we’re more alert and active; when we sleep (or prepare for it), breathing deepens, our heart rate slows and the parasympathetic nervous system is activated.
Thus, whilst you may be jet lagged and tired and not particularly feel like exercising, if you can bring yourself to move about and get your heart rate up, you may be able to wake your body up a little at times when you need to be awake.
Exercising shortly after waking up is reported to be an effective way to establish a healthy circadian rhythm in normal life. Hence, once you arrive at your destination, if possible it could be a good idea to exercise right after waking up (according to your desired sleep/wake schedule) to reinforce in your body that now is the time to be awake, regardless of what your biological clock thinks the time is.
Melatonin Supplementation
After reading about the use of melatonin last year, I was convinced that it was a useful supplement to take. It seems to have beneficial effects on sleep parameters and metabolism (although more research is definitely needed), which motivated me to take it every night, something which I still do and won’t be stopping unless there is convincing reason to.
There is variation in the research (which is normal on topics like sleep, which are complex and have many relevant and hard-to-control factors), but generally one of its most prominent effects is the normalization of disturbed sleep patterns, such as those related to shift-work and jet lag.
I will be publishing an article on this topic in more detail in the near future, but for now, it is enough to say that we can take melatonin at a specific time relative to when we want to sleep to establish our sleep pattern. Normally this would be about an hour before the time we want to sleep, but in the case where we want to adjust our sleep pattern, we can take it a bit earlier, for example, 2–4 hours before.
P.S. Don’t overthink the dosage; the literature is very clear that timing is way more important than the dosage. Between 0.3–3mg will be fine.
Prepare Early
It is advisable to start modifying your sleep schedule before embarking on a trip. For example, if you are travelling west, you can start going to bed and waking up earlier and earlier, so that the difference is not too great when you arrive.
Although this is a useful tactic, it should be used with caution due to the possibility of being sleep deprived in the days before the trip and arriving even more tired when you reach your destination. Therefore, be sure to start adjusting in plenty of time (maybe over the course of a week or two) and do it gradually to avoid giving your body a shock.
Caffeine
Caffeine has a pretty bad reputation because too often people use it inappropriately, evoking negative effects such as interference with sleep.
However, we can use these effects to our advantage. If you have just travelled to a place where you need to wake up at a reasonable hour but your body thinks it’s the middle of the night, it’s likely that you won’t generate many of the substances that indicate it’s time to wake up, like cortisol that is released every morning and gives you the energy to get up and start your day.
As a stimulant, one of the effects of caffeine is the stimulation of cortisol release, which signals to your body that it’s time to be awake. You may have to take a bit more than normal to feel the same level of stimulation, though this is simply because the baseline level of stimulating hormones in your body is also lower than normal.
But be careful; you don’t want to keep using it mindlessly throughout the day because you want to stop in time to let your body eliminate it and be ready to sleep at night. If not, it’s possible that, even though you’re tired, you won’t sleep well and the cycle will continue.
The time required to process caffeine varies between people, but generally, it tends to be quite long, around 8–10 hours. That’s why it’s recommended in everyday life to stop taking it around 2 pm or so (but I always recommend before 12, just in case), and when travelling it’s no different. So even if you feel very tired and need a boost, I would recommend resisting these sensations to establish your sleep rhythm more quickly.
What To Do When You Can’t Sleep
Having dealt with (moderate) sleep problems in the past, I have learned a few things about insomnia. One thing I have learned is that during an episode of insomnia (which you can expect if you’re travelling eastward), you have to prevent yourself from getting too frustrated. Obviously, this is much easier said than done, but the thing is that many people begin to get irritated when they can’t sleep, tossing and turning and constantly changing position, and thinking more and more about the amount of sleep they are losing.
However, the consequences of these actions make it even harder to sleep. The physiological consequences of irritation are a higher heart and respiratory rate and elevated cortisol; tossing and turning constantly means that you are always changing the position of your body, which in turn makes it more difficult to find a comfortable posture; and both of these contribute to an increase in body temperature. All of this is the opposite of what is needed to initiate sleep. This is not an easy situation to be in (we’ve probably all been there at least once and understand these feelings), so having some tricks to use in this situation would be helpful.
The first thing is to know beforehand that this can happen. That is, recognizing before going to bed that there is a possibility of not sleeping as quickly as you would like so that you are more mentally prepared when it happens. I find that this helps me stay calm in such cases.
Second, try to sleep at a realistic time with respect to your destination and your place of origin. Your destination time may already be quite late, but if your body thinks it’s early, you may have difficulty sleeping. In the case that you try to sleep so early, it is possible that you will increase these feelings of irritation and frustration, which are not only unpleasant but can also further interfere with the problem. So perhaps it would be better to do something until you feel like you can sleep without spending so much time in your bed.
Related to this, if you find yourself in a situation where you can’t sleep and you’re not sleepy, you can consider getting up and doing something, such as reading, drawing, or engaging in very light physical activity, such as stretching or walking. Actually, these are general recommendations for people who have difficulty falling asleep, and the idea is to do something to tire your brain and distract your mind from the insomnia. The activity you choose should be gentle and something that requires minimal light and is not stimulating, such as something that does not involve a screen or something that does not raise your heart rate too much. When you feel tired, you can go back to bed and try to sleep again.
And finally, what I do most in these situations is meditate. Apart from sleeping itself, meditation is probably one of the most relaxing things you can do for your body and mind, and certainly one of the healthiest. Since meditation requires regular practice, this advice may not be as useful if you don’t practice it regularly, but if you do, you can see this situation of not sleeping as an opportunity to practice more, which is always beneficial. In this way, you have turned a negative situation into a positive one, in turn practicing one of the healthiest possible habits. Furthermore, since meditation relaxes your mind and body, it is likely that you will fall asleep faster than lying in bed ruminating. And if you’re not yet into meditation, this can be a good opportunity to start…
Don’t Let Jet Lag Defeat You
My last piece of advice is not to submit to defeat. Although I’m a strong advocate for sleep for a healthy life, I’ve noticed in recent years that a bad night’s sleep does not necessarily mean you will have a bad following day.
I’ve put a lot of effort into improving my sleep hygiene in recent years, which means I usually sleep well (compared to before when this was not the case). But still, there are times when, for whatever reason, I might sleep poorly. On such occasions, I have learned that it’s possible to have a good day and function well, despite suboptimal sleep, with the belief that you can do so being a crucial component. You have to believe that you can do what you have to do as usual, and not assume that because you have slept badly, you will perform poorly.
The mind is powerful and we are heavily influenced by our thoughts. Sometimes, even when we are tired, sleep deprived, and out of our normal rhythm, we can put on our game face, dig our heels in, and get what we need to do done.
