Feeling tired? Humans may need more sleep during the winter, new study suggests
Feeling like you want more rest during these cold, darker months? You're not alone. New research suggests that humans may need more sleep in the winter.
According to a study published Friday in the peer-reviewed journal Frontiers in Neuroscience, people with sleep-related difficulties experience longer REM sleep in the winter compared to other seasons.
REM, or rapid eye movement, sleep is an important stage of sleep "associated with dreaming and memory consolidation," the Sleep Foundation says. As Friday's study notes, REM sleep is also known to be linked to the circadian clock – an internally-driven rhythm impacted by the day and night's changing light.
Even though the patients surveyed had experienced disrupted sleep and were based in an urban environment – which sees greater noise and light population – the German researchers found notable seasonal changes in REM sleep.
Participants experienced REM sleep that was 30 minutes longer in the winter than that in the summer.
"Seasonality is ubiquitous in any living being on this planet," Dr. Dieter Kunz, one of the study's authors based at St. Hedwig Hospital's Clinic of Sleep & Chronomedicine in Berlin, said in a news release.
"Even though we still perform unchanged, over the winter human physiology is down-regulated, with a sensation of 'running-on-empty' in February or March," Kunz added.
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The researchers also found that total sleep time appeared to be up to one hour longer in the winter compared to the summer, but that was "not significant" statistically.
How the study was performed
A team of scientists from the Charité Medical University of Berlin recruited 292 patients that had previously undergone studies, called polysomnographies, for people with sleep-related difficulties and/or potential sleep disorders at St. Hedwig Hospital.
The researchers excluded:
Patients who were taking sleep medications.
Patients who had technical failures during their polysomnography/
Patients with REM sleep latency that suggested their first REM sleep episode had been skipped.
After those exclusions, 188 patients remained.
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Seasonal changes in sleep could be 'even greater' for general population
The studies acknowledged that the participants' sleep-related difficulties and/or disorders could affect the results – with Kuntz noting that "this study needs to be replicated in a large cohort of healthy subjects."
The current findings suggest that seasonal sleep changes "may be even greater if generalized to a healthy population," the study says.
These seasonal changes may also impact recommendations for sleep routines.
"For many people, the time to wake up is more strongly controlled by their employer’s business hours or school times than by their internal clock," the study notes. "Adjustment of sleep schedule can, therefore, only be controlled by choosing the time to go to bed"
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Going to sleep earlier in the winter, for example, may help you get more sleep.
Some also argue that there could be benefits from societal, work and/or school accommodations that would allow people to get the rest they need during the changing seasons.
"In general, societies need to adjust sleep habits including length and timing to season, or adjust school and working schedules to seasonal sleep needs," Kunz said.
This article originally appeared on USA TODAY: More sleep may be needed during winter months, new study suggests