Conquering jet lag? Tips for a smoother transition.

Living in a small nation with one of the world’s best airports, it’s no surprise that Singapore’s residents are frequent travellers, especially at this time of year.  This means that most of us will have first-hand experience of how travel can disrupt sleep.

Jet lag is the most well-known effect of travel. This occurs when your biological clock is misaligned with your new location, meaning you may find yourself wide awake staring at the ceiling in the middle of the night, or falling asleep during the day.  However, travel can affect sleep in a number of other ways.  For example, your sleep schedule may be disrupted, or you may have to sleep in an uncomfortable in-flight environment.

Researchers in our lab recently collaborated with scientists at Oura to characterise how travel affects sleep.  We analysed Oura ring data from over 60,000 trips; including the days before and after the travel itself it totalled ~1.5 million nights of sleep.

We found that sleep can be disrupted before the trip even starts.  Sleep on the night prior to travel is often shortened, because people have to wake up early to get to the airport in time for their flight.  Long eastward flights are the exception though – they tend to leave later in the day and be overnight flights.  It’s easy to forget about this aspect of travel in Singapore where the airport is only about 30 minutes away from anywhere on the island.

As most travellers know, jet lag is worse when travelling east rather than west.  This is because it’s easier to delay going to bed than it is to go to sleep earlier when you’re not tired.  Our results were consistent with this intuition, showing that it took longer for the body clock to realign following eastward travel.  We also showed that sleep architecture (that is, how long you spend in light, deep and REM sleep) is more affected by eastward travel and this can take up to a week to recover.

Another interesting finding was that sleep tends to ‘normalize’ following travel.  That is, people who typically have short sleep tend to sleep longer when they travel (and vice versa).  The same is also true for sleep timing, where early sleepers will sleep later during travel (and vice versa).  This contrasts with weekends where most people sleep longer and later regardless of how they sleep during the week.  This may be because travel (especially vacation travel) frees you from your usual pressures and habits, allowing you to come into better alignment with environmental time cues.

Overcoming jet lag can be difficult and, unfortunately, there are currently no foolproof techniques to beat it. You’ll need to find what works for you, and here are things you need to know that will help you build your own strategy:

(1) It may be possible to ‘pre-pay’ your jet lag by adjusting your sleep timing towards the time you’ll go to sleep at your destination before you travel.  But this is only an option if you have the flexibility to move your sleep.

(2) When at your destination, it’s best to try to adopt the sleep/wake timing of your destination as much as possible, even if it is difficult for the first few days.

(3) Because light is the strongest environmental signal that tells our body about the new time zone, it’s a good idea to get outside during the day as much as possible; outdoor light is much stronger than indoor light.

(4) Coffee can be used to help you stay awake, but naps and melatonin should be used very carefully.  If you have a nap or take melatonin at the wrong time of day, it can actually slow recovery from jet lag.

The information you’re providing about your travel in the NUS 1000 staff edition study will allow us to follow up on this research with more precise flight timing information and a different distribution of flight routes.

We wish you safe travels this summer and a quick recovery from any travel-related sleep disruption you may experience!