Do humans need to hibernate, too? What the research shows

Jan 22, 2024, 11:31 AM

Sleeping more in the winter could be due to seasonal or behavioral causes.
Mandatory Credit:	Dmytro...

Sleeping more in the winter could be due to seasonal or behavioral causes. Mandatory Credit: Dmytro Betsenko/Moment RF/Getty Images

(CNN) — Does the colder season have you dragging during the day, feeling like the amount of sleep you usually get in other parts of the year doesn’t seem to be enough now?

“If you feel like sleeping more in the winter, you’re not alone,” said Dr. Raj Dasgupta, an associate professor of clinical medicine at Huntington Memorial Hospital in Pasadena, California, citing research that found at least a third of American adults reported they sleep more in the winter.

“Sleep needs for most adults are somewhere between (seven to nine) hours per night, and that is consistent no matter how cold or dark it gets outside,” said Dasgupta, who is also associate program director of internal medicine residency at Huntington. “However, it is common to feel like you are sleeping more during the winter due to the fact that we lose an hour of daylight when we enter standard time, which is associated with the early onset of darkness.”

When compared with animals, the effects of seasonality on human sleep were thought to amount to little to none until recently when a study published in February 2023 found otherwise: The 188 patients who underwent sleep studies at St. Hedwig Hospital in Berlin slept about an hour longer in winter than they did in summer, which the authors said wasn’t statistically significant. But participants did get 30 more minutes of rapid eye movement, or REM, sleep during winter.

The REM phase of sleep is the sweet spot of sleep cycles, characterized by more dreaming and faster heart rate and breathing than in other stages. It’s “an essential stage of sleep that helps with memory, concentration, mood regulation and immune function,” Dasgupta said.

The desire for, or occurrence of, more sleep during winter may have to do with how light fluctuates throughout the year, or with the behavioral and mental health changes that can result. Here’s what experts think you should know about the science and whether you should make any adjustments.

How light affects sleep

“Our bodies receive cues from the sun when it comes to our circadian rhythm, meaning that when it is bright outside we tend to be active, but when the sun goes down, you may tend to feel tired,” Dasgupta said. “The decrease in sunlight causes an increase in melatonin, a hormone made in the body that regulates sleep-wake cycles.”

With the earlier production of melatonin during winter, “it would be natural to assume that a healthy person also would need more sleep during the winter,” said Dr. Carleara Weiss, a research assistant professor in the Center for Nursing Research at the University of Buffalo.

And light influences not only sleep quantity but also sleep quality. “REM sleep is highly affected by light and darkness, so when during the winter months we have less light, the body is going to basically overcompensate by giving more REM sleep,” said Dr. Joshua Tal, a New York City-based clinical psychologist specializing in sleep issues.

Needing more sleep during the winter may also be due to what’s known as “social jet lag,” experts said, meaning that the fun, late nights you had all summer may be why you’re having trouble falling asleep in winter or feeling your body overcompensate with more sleep.

“Your body is not used to this earlier time, and it’s hard to fall asleep,” Tal said. “Your clock is delayed.”

Other behavioral reasons include “holiday stress, indulgence in a wide variety of foods and treats, alcohol intake and skipping out on workouts,” Dasgupta said.

Adjusting to the seasons

Humans still don’t need to hibernate, Weiss said, nor can we afford to due to our social and occupational obligations. “But we can make adjustments to perform in a better way, to rest in a better way during winter,” she said.

Because of how the light shifts in winter may affect our circadian rhythms, sleeping a little more could help you be more alert for a schedule requiring you to be outside while it’s dark, Tal said. Alternatively, pushing work or school start times later would also be helpful since only having to be out in the daytime would help people feel more alert.

“To help our bodies make this transition from sleep to wake, it’s important to have light exposure in the morning during winter months,” Weiss said. “Along with that, it’s important to keep a consistent bedtime and wake-up times.”

If your schedule doesn’t allow for natural light exposure before work, you could try light therapy, the primary treatment for seasonal affective disorder — which can be another reason for sleeping more during wintertime. The treatment involves exposing yourself to a light box with 10,000 lux minimum for at least 30 minutes. (Lux is a unit of measurement for light level intensity.)

“Making sure that your sleeping environment is conducive to sleep is important,” said Dr. Jennifer Martin, a professor of medicine at the David Geffen School of Medicine at UCLA and immediate past president of the American Academy of Sleep Medicine. “And reach out to either a trusted health care professional or directly to a mental health professional if you notice that you’re struggling with seasonal depression.”

The-CNN-Wire™ & © 2024 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.

KSL 5 TV Live

National News

Chuck Perkins's 1980 carving of a cheetah went on a long journey to find its way home. (Courtesy Ce...

Sydney Bishop, CNN

After 15 years, a social media post helps reunite a family with a long-lost heirloom

A social media post helped a family be reunited with a family heirloom - 15 years later.

8 hours ago

Ben Van Leeuwen scoops Kraft Mac & Cheese flavored ice cream Wednesday, May 15, 2024, in the Br...

Dee-Ann Durbin, The Associated Press

Sour Patch Kids Oreos? Peeps Pepsi? What’s behind the weird flavors popping up on store shelves

Van Leeuwen Ice Cream usually draws customers with gourmet takes on classics like vanilla and pistachio. But occasionally, the artisanal ice cream maker headquartered in New York slips in what it calls a “shock flavor,” like Hidden Valley Ranch or pizza.

10 hours ago

Former President Donald Trump appears at Manhattan Criminal Court on Monday, May 20, 2024 in New Yo...

Associated Press

Prosecution rests its case in Donald Trump’s hush money trial

Donald Trump's hush money trial entered its final stretch with the prosecution resting its case late Monday afternoon following the conclusion of star witness Michael Cohen 's testimony.

10 hours ago

Crews work to move the cargo ship Dali in Baltimore, on May 20. The vessel on March 26 struck the F...

Holly Yan, Elizabeth Wolfe, Pete Muntean and Gregory Wallace, CNN

Dali cargo ship now docked after it destroyed Baltimore bridge; investigations still underway

After 55 days stuck in the Patapsco River, the Dali cargo ship was hauled away from the site of its catastrophic crash into the Francis Scott Key Bridge – a crucial step toward fully reopening the busy Port of Baltimore.

13 hours ago

ROHNERT PARK, CALIFORNIA - APRIL 17: In an aerial view, a sign is posted on the exterior of a Red L...

Michelle Chapman and Dee-Ann Durbin, AP Business Writers

Red Lobster seeks bankruptcy protection days after closing dozens of restaurants

Casual dining chain Red Lobster has filed for bankruptcy protection late Sunday, days after shuttering dozens of restaurants.

13 hours ago

NEW YORK, NEW YORK - MAY 20: Former U.S. President Donald Trump with attorney Todd Blanche (L) retu...

Michael R. Sisak, Jennifer Peltz, Jake Offenhartz and Alanna Durkin Richer

Michael Cohen says he stole from Trump’s company as defense presses key hush money trial witness

Former Donald Trump attorney Michael Cohen admitted to jurors in the Republican’s hush money trial that he stole tens of thousands of dollars from Trump’s company.

14 hours ago

Sponsored Articles

Electrician repairing ceiling fan with lamps indoors...

Lighting Design

Stay cool this summer with ceiling fans

When used correctly, ceiling fans help circulate cool and warm air. They can also help you save on utilities.

Side view at diverse group of children sitting in row at school classroom and using laptops...

PC Laptops

5 Internet Safety Tips for Kids

Read these tips about internet safety for kids so that your children can use this tool for learning and discovery in positive ways.

Women hold card for scanning key card to access Photocopier Security system concept...

Les Olson

Why Printer Security Should Be Top of Mind for Your Business

Connected printers have vulnerable endpoints that are an easy target for cyber thieves. Protect your business with these tips.

Modern chandelier hanging from a white slanted ceiling with windows in the backgruond...

Lighting Design

Light Up Your Home With These Top Lighting Trends for 2024

Check out the latest lighting design trends for 2024 and tips on how you can incorporate them into your home.

Technician woman fixing hardware of desktop computer. Close up....

PC Laptops

Tips for Hassle-Free Computer Repairs

Experiencing a glitch in your computer can be frustrating, but with these tips you can have your computer repaired without the stress.

Close up of finger on keyboard button with number 11 logo...

PC Laptops

7 Reasons Why You Should Upgrade Your Laptop to Windows 11

Explore the benefits of upgrading to Windows 11 for a smoother, more secure, and feature-packed computing experience.

Do humans need to hibernate, too? What the research shows