Here's what happens to your body when clocks 'fall back' an hour

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Here's what happens to your body when clocks 'fall back' an hour

2025-10-27 21:01 Last Updated At：21:20

Plan on a glorious extra hour of sleep as most of America “falls back” into standard time. But make sure to get outside for some morning sun, too — it’ll help your body clock reset faster.

Daylight saving time ends at 2 a.m. local time Sunday, which means you should set your clock back an hour before you go to bed. Standard time will last until March 8 when we will again “spring forward” with the return of daylight saving time.

There’s a lot of grumbling about the twice-a-year time changes. The spring switch tends to be harder, losing that hour of sleep we allegedly recover in the fall. But many people also mourn fall's end of daylight saving time, when days already are getting shorter and moving the clocks can mean less daylight after school or work for exercise or outdoor fun.

Some health groups, including the American Medical Association and American Academy of Sleep Medicine, have long urged adopting standard time year-round.

New research from Stanford University agrees, finding that switching back-and-forth is the worst option for our health. The study showed sticking with either time option would be a bit healthier, but they found permanent standard time is slightly better — because it aligns more with the sun and human biology, what’s called our circadian rhythm.

“The best way to think about it is as if the central clock were like a conductor of an orchestra and each of the organs were a different instrument,” said Jamie Zeitzer, who co-directs Stanford’s Center for Sleep and Circadian Sciences.

More light in the morning and less at night is key to keeping that rhythm on schedule — all the instruments in sync. When the clock is regularly disrupted by time changes or other reasons, he said each of the body's organ systems, such as the immune system or metabolism, “just works a little less well."

Most countries do not observe daylight saving time. For those that do — mostly in North America and Europe — the date that clocks are changed varies. In the U.S., Arizona and Hawaii don’t change and stay on standard time.

Here’s what to know about the twice-yearly ritual.

The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert. The patterns change with age, one reason that early-to-rise youngsters evolve into hard-to-wake teens.

Morning light resets the rhythm. By evening, levels of a hormone called melatonin begin to surge, triggering drowsiness. Too much light in the evening — whether from later time outdoors doing daylight saving time or from artificial light like computer screens — delays that surge and the cycle gets out of sync.

And that circadian clock affects more than sleep, also influencing things like heart rate, blood pressure, stress hormones and metabolism.

Even an hour change on the clock can throw off sleep schedules because even though the clocks change, work and school start times stay the same.

The spring change to daylight saving time can be a little rougher as darker mornings and lighter evenings make it harder to fall asleep on time. Those first few days have been linked to increases in car crashes and even an uptick in heart attacks.

Some people with seasonal affective disorder, a type of depression usually linked to the shorter days and less sunlight of fall and winter, may struggle too.

Many people easily adjust, like how they recover from jet lag after traveling. But a time change can add pressure on shift workers whose schedules already are out of sync with the sun, or those regularly sleep-deprived for other reasons.

About 1 in 3 U.S. adults sleep less than the recommended seven-plus hours nightly, and more than half of U.S. teens don’t get the recommended eight-plus hours on weeknights.

Chronic sleep deprivation is linked to heart disease, cognitive decline, obesity and numerous other problems.

In both fall and spring, changing bedtimes by as little as 15 minutes a night in the days before the change can help ease into it.

But sunshine in the morning is critical to helping reset your circadian rhythm for healthful sleep. If you can’t get outdoors, sit by windows.

In Congress, a bill named the Sunshine Protection Act that proposes making daylight saving time permanent has stalled in recent years.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

An Ebola center is burned in Congo as fear and anger grows over the outbreak

BUNIA, Congo (AP) — People set fire to an Ebola treatment center in a town at the heart of the outbreak in eastern Congo on Thursday after being stopped from retrieving the body of a local man, a witness and a senior police officer said, as fear and anger grow over a health crisis that doctors are struggling to contain.

The arson attack in Rwampara reflects the challenges of health workers trying to curb a rare Ebola virus by using stringent measures that might clash with local customs, such as burial rites. The disease has been spreading for weeks in a region lacking in health facilities and where armed conflict has displaced many people.

The dangerous work of burying suspected victims is being managed wherever possible by authorities because the bodies of those who die from Ebola can be highly contagious and lead to further spread when people prepare bodies for burial and gather for funerals.

That policy can be extremely unpopular with victims' families and friends, who aren't given the chance to bury their loved ones.

The center in Rwampara was burned by local youths who became angry while trying to retrieve the body of a friend who had apparently died of Ebola, according to a witness who spoke to The Associated Press by telephone.

“The police intervened to try to calm the situation, but unfortunately they were unsuccessful,” said Alexis Burata, a local student who said he was in the area. "The young people ended up setting fire to the center. That’s the situation.”

An AP journalist saw people break into the center and set fire to objects inside and also to what appeared to be the body of at least one suspected Ebola victim that was being stored there. Aid workers fled the treatment center in vehicles.

Deputy Senior Commissioner Jean Claude Mukendi, head of the public security department, Ituri Province, said it was due to youths who didn't understand the protocols required for burying suspected Ebola victims.

“His family, friends, and other young people wanted to take his body home for a funeral even though the instructions from the authorities during this Ebola virus outbreak are clear," Mukendi said. "All bodies must be buried according to the regulations."

Hama Amadou, the field Coordinator for the humanitarian organization ALIMA, which had teams working at the center, said later that calm had been restored and the aid teams were continuing their work at the center.

The flash of anger underlined the complications faced by both Congolese authorities and an array of aid agencies trying to stem an outbreak the World Health Organization has declared a public health emergency of international concern.

There are 148 suspected deaths and nearly 600 suspected cases, according to the U.N., with two cases including one death in neighboring Uganda. But the head of the WHO has said the outbreak is almost certainly much larger and has also expressed concern over the speed of the spread.

The risk of the outbreak spreading globally is low, the WHO has said, but high regionally with the Ituri Province at the center of the outbreak bordering Uganda and South Sudan.

“The priority now is to act quickly and work closely with communities, as the coming days are critical,” said Ariel Kestens, the head of the International Federation of Red Cross and Red Crescent Societies delegation in Congo.

Health workers and aid groups have said they are in dire need of more supplies and staff to respond. Also, there is no available vaccine or medicine for the Bundibugyo strain responsible for the outbreak.

An expert said this week it would be at least six to nine months before one would be available.

The virus spread undetected for weeks following the first known death in late April as Congolese health authorities tested for a different Ebola virus more commonly responsible for outbreaks in the country.

On Thursday, the M23 rebel group that controls parts of eastern Congo reported a confirmed case near the major city of Bukavu, some 500 kilometers (310 miles) south of the outbreak’s epicenter in Ituri Pronvince. The person died, M23 said in a statement.

As well as Ituri, other cases had been confirmed in North Kivu province and two in Uganda. But the announcement by M23 was the first confirmation of a case in South Kivu.

Health officials have not yet found “patient zero,” according to the WHO.

Investigations are continuing into the source of the outbreak, but “given the scale, we are thinking that it has started probably a couple of months ago,” said Anaïs Legand, a viral hemorrhagic fevers expert at the WHO.

India and the ⁠African Union said Thursday that the ⁠India-Africa ⁠Forum Summit, scheduled to be held next week in ‌New Delhi, had been postponed due to ⁠the “evolving health situation in parts of Africa.”

On Wednesday, Congo’s soccer team canceled a three-day World Cup preparation training camp and a planned farewell to fans in the capital Kinshasa because of the Ebola outbreak.

The U.S. Department of Homeland Security announced that any flights carrying American citizens or U.S. permanent residents who had visited Congo, Uganda or South Sudan in the previous 21 days would be redirected to Washington Dulles International Airport from Thursday, where there would be enhanced Ebola screening.

The U.S. had already put in place restrictions banning other travelers who had been in those three countries in the previous 21 days from entering the U.S.

Pronczuk reported from Dakar, Senegal and Imray from Cape Town, South Africa. Associated Press writers Jamey Keaten in Geneva; Jean Yves Kamale in Kinshasa, Congo; and Wilson McMakin in Dakar, Senegal contributed to this report.

For more on Africa and development: https://apnews.com/hub/africa-pulse

The Associated Press receives financial support for global health and development coverage in Africa from the Gates Foundation. The AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.