Electronic clocks and smartphones have long made it possible to reduce the risk of falling back asleep after the alarm has sounded, thanks to the “snooze” function. But it is not without consequences for health, if only because it allows you to return to a phase of deep sleep, sending the wrong signal to the brain.

At least, this is what has been previously suggested by several studies carried out on the subject. Now, new research conducted by researchers from Stockholm University challenges these observations, by examining the impact of the snooze function on sleep and sleepiness, mood, stress, and cognitive abilities.

They conducted two studies, the first based on the responses of 1,732 people about their morning habits, in particular the frequency with which they hit “snooze” to grab a few extra minutes’ sleep. Snoozers were found to primarily comprise young adults or evening people, most of whom said they use this function because they feel too tired to wake up when the alarm sounds.

Then, 31 people who regularly snooze took part in the second study, conducted over two nights in a sleep laboratory. They were allowed to snooze for 30 minutes one morning, but had to get up straight away the next morning.

Published in the Journal of Sleep Research, these studies reveal that the snooze function is not as harmful to health as one might think. In fact, it may even enable users to wake up with more alertness.

Above all, the results suggest that although the participants’ sleep was slightly disrupted by the repeating alarm, the majority “slept well”. Indeed, the function had little or no effect on the total length of their night’s sleep, with no “clear effects” on mood, sleepiness or the amount of cortisol – the stress hormone – in saliva.

“Those who snooze sleep slightly shorter and feel more drowsy in the morning compared with those who never snooze,” said lead author Tina Sundelin. “But there were no negative effects of snoozing on cortisol release, morning tiredness, mood, or sleep quality throughout the night.”

This research also suggests that hitting the snooze button may boost certain cognitive abilities – at least immediately upon waking up.

“Half an hour of snoozing does not have negative effects on night sleep or sleep inertia, the feeling of not quite being alert in the morning. If anything, we saw positive outcomes, such as a decreased likelihood of waking from deep sleep.

“Participants were also a bit more quick-thinking right when they got up,” the researchers concluded. All the more reason to hit that snooze button in the mornings!