A NEW study has found why jet lag may feel worse on the way home to Ireland, compared to when departing.
Scientists have determined that the reason for this is that jet lag is more severe when travelling eastwards.
In the largest study ever done of its kind, researchers from the Centre of Sleep and Cognition at the NUS Yong Loo Lin School of Medicine in Singapore found that jet lag has an even bigger impact than was believed.
Other studies surrounding jet lag were previously conducted under controlled lab conditions, or involved specific groups like athletes or army workers – and the characteristics may not have reflected the general group of passengers.
Scientists found that sleep disruption as a result of travel takes longer to recover from than it was previously thought.
Although sleep duration can recover quickly, sleep timing can take “significantly longer” to get back on track.
This is more so the case when travelling across time zones.
It is even more likely to happen when passengers travel east – as they are “losing” time.
The body clock, called the circadian rhythm, tends to be less confused when travelling towards the west as the direction “prolongs” the experience of a normal day to night cycle.
This cycle usually lasts around 24.5 hours, but when travelling eastwards, it runs opposite to the body clock.
The study found that shorter trips of up to three time zones were severely impacted by jet lag.
It was also found that young adults experience more negative sleep impacts on long flights than those in their 60s.
GREAT TECH
The study was carried out by analysing sleep patterns of passengers during 60,000 trips that spanned more than 965km, alongside the Finnish tech firm Oura Health.
1.5 million nights of anonymous data were collected from the Oura ring.
This smart device has been hugely successful in recent years, and is used to track sleep and physical activity.
And if you usually sleep on a long-haul flight, this could also negatively impact you as you may experience impaired performance and more sleepiness during the day.
But in some good news, it was found that the impacts don’t last too long as sleep duration usually goes back to normal within 2 days.
PERSISTENT IMPACTS
Though the impacts to sleep timing and structure, where you may find yourself waking up more during the night, can take over a week to settle down.
This is amplified by travelling east, and crossing through several timezones.
The study’s lead author and senior research fellow at NUS Medicine, Dr Adrian Willoughby said: “We’ve known for some time that jet lag is a challenge for travellers, but this study provides data-driven evidence of just how persistent the impacts are, particularly when it comes to adjusting sleep timing to a new time zone.
“Crossing time zones complicates this recovery by disrupting the ability to fall asleep at the appropriate local time.”
