A recent collaborative study conducted by researchers at the Center for Sleep and Cognition at the NUS Yong Loo Lin School of Medicine (NUS Medicine) and ŌURA has shed light on the impact of travel-related sleep disruption. The study, titled “Insights about Travel-Related Sleep Disruption from 1.5 Million Nights of Data,” was published in the prestigious journal SLEEP on 24 March 2025.
The researchers analyzed sleep patterns during over 60,000 trips of more than 100km and utilized a vast dataset of 1.5 million nights of de-identified data collected from the Oura Ring. This study represents the first large-scale, real-world investigation into jet lag recovery, providing valuable insights for travelers.
Lead researcher Adrian Willoughby, a Senior Research Fellow at NUS Medicine, highlighted the persistent effects of jet lag on sleep timing and architecture when traveling across time zones. While sleep duration may recover relatively quickly within a couple of days, adjusting to the new time zone in terms of sleep timing and structure can take longer, sometimes more than a week.
Jet lag is a common challenge for travelers, exacerbated by factors such as early wake-up times for flights and disrupted sleep on overnight journeys. The study revealed that crossing time zones complicates the recovery process, making it difficult to fall asleep at the appropriate local time.
Key findings from the study include the observation that sleep duration typically returns to normal within a few days post-travel, while changes in sleep timing and structure may persist for over a week. Eastward travel and crossing multiple time zones were found to amplify the disruption, with shorter trips experiencing more severe jet lag.
Interestingly, the study found minimal differences in travel-related sleep disruption between men and women, although older travelers appeared to experience slightly less impact. The research also emphasized the importance of measuring habitual sleep patterns before and after travel to better understand the recovery process.
Professor Michael Chee, Director of the Center for Sleep and Cognition at NUS Medicine, highlighted the value of wearable devices like the Oura Ring in tracking health behaviors over time. Such devices provide valuable insights for travelers to assess their sleep habits and recovery post-travel.
Future research aims to explore lifestyle factors that may influence the speed of recovery from travel-related sleep disruption, as well as the effectiveness of interventions such as light exposure and melatonin ingestion in real-world settings.
This groundbreaking study offers valuable insights into the challenges of jet lag and sleep disruption during travel, providing a data-driven understanding of the recovery process. By leveraging large-scale datasets and real-world observations, researchers hope to enhance strategies for managing sleep disturbances associated with travel.
