When the alarm goes off in the early morning, it’s tempting to hit the snooze button and curl back under the warm covers for a few more minutes of slumber. This repeated postponing of the buzzer is often thought of as a bad habit—one that creates not only a lazy start to a day but also a fragmented sleep pattern that’s detrimental to health. Now, however, a growing body of recent research is contradicting this notion.
A new study published in the Journal of Sleep Research found that people who regularly press the snooze button lost only about six minutes of sleep per night—and that it didn’t affect their morning sleepiness or mood. In fact, tests showed that it actually improved cognition. This adds to research in 2022 that also found chronic snoozers generally felt no sleepier than nonsnoozers.
“Snoozing for a limited time in the morning is probably not bad for you,” says the new study’s lead author Tina Sundelin, a sleep researcher at Stockholm University. She says that her study is one of few that have directly tested snoozing’s effect on sleep health, and it supplies evidence that snoozing doesn’t break up sleep in a harmful way.
Scientific American spoke with sleep experts on the science of snoozing and how the habit may actually be good for you—if you do it right.
The Potential Benefits of Snoozing
Snoozing does shorten sleep, Sundelin says, but she maintains that it’s not as bad as scientists once thought. Past research has suggested that the extra minutes snoozers get don’t really help them feel more rested—and repeatedly waking up and trying to sleep again has been thought to prevent the restorative stages of sleep, including rapid-eye movement (REM). Other research has suggested that waking someone in the middle of their sleep cycle causes them to feel sleepier throughout the day. “If you disturb someone’s sleep, it’s not good-quality sleep, and they often feel tired afterwards—but this [idea] is based on a whole night of sleep fragmentation,” explains Sundelin, who adds that most theories about snoozing are “inferred from what we know about sleep in general.”
In the new study, Sundelin found that snoozing the alarm for a half hour benefited chronic snoozers—people who delay the alarm two or more times a week and almost always fall back asleep between alarms. Thirty-one such chronic snoozers who were observed in the study slept well throughout the night and only showed signs of fragmented sleep in the last 30 minutes before getting up, which is typically around the time that people first hit the snooze button. But this fragmented sleep “didn’t have a big enough impact to make them tired” throughout the rest of the day, Sundelin says.
Sundelin’s research also suggests that snoozing may help people shake off morning drowsiness by easing the transition from deep sleep to a lighter stage. A good night’s rest typically involves four to five sleep cycles, each made up of four stages. Light sleep happens in the first two stages of nonrapid eye movement (NREM). This is when muscles start to relax, and brain activity slows, along with breathing and heart rate—but a person can still be easily woken. As the night goes on, people progressively reach deeper stages. It gets harder to wake up during the third and final stage of NREM and the first stage of REM. A person who receives a phone call during these stages, for example, may be less likely to hear it or remember answering.
Abruptly waking up, especially amid deep sleep, can prolong sleep inertia—drowsy state of transition to wakefulness in which one may feel disoriented or struggle with adjusting to being awake. This is where snoozing may help, Sundelin says: people who squeeze little naps between alarms can more effectively shift out of deep sleep and wake up during lighter sleep. This may help them decrease sleep inertia and feel more alert and energetic in the morning.
The additional light slumber may also aid cognition, Sundelin’s results show. Even with their last half hour of sleep fragmented, snoozers didn’t feel more tired during the day. They were also alert enough to perform well on cognitive tests of processing speed, episodic memory and executive functioning, as well as simple arithmetic. A second cognitive test showed these benefits continued for at least 40 minutes after waking up.
Sundelin hypothesizes that snoozing prevented people’s brain from quickly reverting to deeper sleep stages. Snoozers also showed higher levels of cortisol, a hormone involved in wakefulness, compared with people who slept uninterrupted throughout the whole night. “It’s possible the cortisol awakening response started slightly earlier [in snoozers], and this could have helped the brain to finish these tasks,” Sundelin says.
The relationship between snoozing and cognition still needs further research, says sleep scientist Cassie Hilditch of San José State University, who was not involved in the recent study. She notes that there has been other work reporting the opposite effect: an improvement in alertness for nonsnoozers and worse cognitive performance in snoozers.
Snoozing Impacts People Differently
Young adults typically press snooze more often than older ones. Thomas Kilkenny, director of the Institute of Sleep Medicine at Staten Island University Hospital, says that adults in their early to mid-20s tend to stay up late and get less sleep overall. Some people’s biological clock—a built-in 24-hour cycle that helps the body regulate processes including wakefulness and sleep—tends to shift toward a “night owl” chronotype during adolescence, reaching a peak “lateness” around age 20. “Partly the fault is that the body just doesn’t want to go to sleep until one o’clock in the morning, even if you have to get up at six to go to school,” Kilkenny says.
Night owl–types, regardless of age, are also more likely to hit snooze. Those with late chronotypes often feel their best in the evening and prefer going to bed closer to midnight. Given that school and work typically start early, however, night owls often have to wake up when they are least alert compared to “morning larks” (people with an early chronotype), Hilditch says. She adds that sleep inertia can be worse when waking up closer to one’s circadian low, a time when alertness is bottoming out. “Therefore, later chronotypes may find it harder to wake up for early classes and workdays given the increased sleep inertia during this time,” Hilditch says.
How to Get the Most Out of Snoozing
The optimal period to spend snoozing is somewhere between 20 to 30 minutes, says Kilkenny, who suggests this is enough to be “refreshing but not too much.” This is equivalent to hitting the snooze button every five to 10 minutes for a total of three or four times. This is likely enough to overcome sleep inertia, which usually lasts 30 minutes or less for someone who isn’t sleep- deprived. Additionally, snoozing for more than half an hour can inch a person closer to the deeper phases of sleep from which it’s harder to get up. This is why people who say they’ve “overslept” sometimes feel groggy or disoriented.
So snoozing can give the body some time to adjust and prepare to get out of bed. This may come in handy for things such as adjusting to the beginning of daylight saving time, when many people lose an hour of sleep, Kilkenny says. But people who regularly wake up without an alarm or who get up the first time it goes off may not get those same benefits if they snooze. Kilkenny says that’s because the body has already had enough time to fully rest.
There is one caveat: snoozing can never replace a good night’s sleep. People who feel they need to snooze for more than 30 minutes and who have difficulty waking up after that may be showing signs of sleep deprivation. If that’s the case, the problem won’t be solved with the touch of a button—and snoozing might, in fact, make things worse. Waking tactics such as the slow-to-rise method (gradually shifting wake-up time 10 to 15 minutes earlier every few days) could help some people—but only those who are already getting enough sleep, Kilkenny says.
There is still much to learn about snoozing’s long-term impact on cognition and the brain. But the new research is a helpful step toward dispelling some of the “lazy” stereotypes often associated with this common morning ritual. So regular snoozers can feel less guilty for catching some extra z’s while hitting the alarm button tomorrow morning.