If you’re concerned that by hitting the snooze button multiple times in the morning you could be hurting your sleep, you can sleep easy: For most people, “snoozing” has no impact on sleep quality, a new study suggests.
What's more, for some, hitting the button multiple times over 30 minutes may spark alertness more quickly than sleeping through without a break, according to the study, published Wednesday in the Journal of Sleep Research.
The study found “that snoozing for 30 minutes in the morning does not make you more tired or more likely to wake up from deep sleep,” the study’s lead author, Tina Sundelin, an associate professor in the department of psychology at Stockholm University in Sweden, said in an email. “For those who usually snooze, it might even be helpful with waking.”
Among the 1,732 adults who filled out a questionnaire about their waking habits in the morning, 69% said they hit the snooze button at least sometimes, especially on weekdays. Many, 60%, said they “most often” or “always” fell asleep between alarms, the result being that, on average, snoozers got just a little less sleep.
Overall, snoozers were more likely to be an average of six years younger than non-snoozers and almost four times more likely to be “night owls.” Snoozers were also three times more likely to report feeling drowsy when they woke up.
The top reason for choosing to snooze rather than have an unbroken stretch of sleep was that a person couldn’t wake up or was too tired. The next two most common reasons were that snoozing feels good and that it allows a person to wake up more slowly or “softly.”
To take a closer look at the impact of snoozing, the researchers recruited 31 people to spend several nights in a sleep lab. All of the people included in this part of the study said they hit the snooze button several times in the morning at least two or more days a week. The participants’ average age was about 27, and none had any sleep disorders, such as insomnia.
On two different nights, the participants were asked to try two methods of waking up: either getting up immediately after the alarm went off or 30 minutes after the alarm went off, pressing the snooze button three times. The total number of hours spent in bed was the same, regardless of whether a person snoozed or not — for example, when the participants were asked to snooze, the first alarm was set 30 minutes before the participants would usually get up.
When the people were told to hit the snooze button, they got six minutes less sleep, on average, the study found, but the overall structure of their sleep was the same.
The participants’ cognitive abilities were tested right after they got out of bed and then again 40 minutes later. When it came to performance on cognitive tests, including recalling past experiences, testing reaction times and solving math problems quickly, snoozing appeared to give an advantage right after people rose. But that advantage disappeared within 40 minutes of getting out of bed.
“When snoozing, as opposed to when having to wake up right away, I would say that they came to alertness quicker, even though there was no difference in how sleepy or alert they felt subjectively,” Sundelin said.
It’s possible that snoozing is preferable to some people because it spreads out the process of waking up, said Marie-Pierre St-Onge, the director of the Center of Excellence for Sleep and Circadian Research at Columbia University’s Vagelos College of Physicians and Surgeons in New York City.
“People who snooze for 30 minutes are actually falling back to sleep between alarms,” said St-Onge, who wasn’t involved with the new research. “Not a deep sleep but a light sleep so that when they had to wake up at the end of 30 minutes they were not being yanked out of a deeper stage of sleep. They might have felt this was a more gentle awakening.”
The people in the second study were all confirmed snoozers, St-Onge said, adding that it might be interesting to run the same experiment with people who typically choose not to snooze.
Dr. Beth Malow, the director of the sleep disorders division and a professor of neurology and pediatrics at the Vanderbilt University Medical Center in Nashville, Tennessee, said two of the reasons for choosing to snooze — that it “feels good” and that it allowed people to wake up more “softly”— were intriguing.
It may be that by waking up in stages, a person avoids being pulled out of REM sleep, said Malow, who also wasn’t involved with the new research. “You might have a harder time if you’re coming out of a dream,” she said. “That can be very jolting.”
It’s not surprising that snoozing is more common among young people, because we already know that sleep cycles are shifted later in teens and young adults, Malow said, adding that it may be that snoozers stop snoozing as they get older.Follow NBC HEALTH on Twitter & Facebook.