Do you press the snooze button in the morning? Many people think snoozing is bad. But a study in Sweden found something different. People who often snooze slept in a lab.

On one morning they snoozed for 30 minutes. They lost only about six minutes of sleep, and their thinking tests were not worse. However, a small study in Japan found the opposite. So, snoozing may be fine for some people.

Many people feel guilty about pressing the snooze button, believing that it breaks up sleep and makes them groggy. However, a Swedish study published in 2023 found something surprising. Researchers asked 31 people who usually snooze to sleep in a laboratory. On one morning they snoozed for 30 minutes, and on another they got up at once.

Snoozing cost them only about six minutes of sleep, and their scores on thinking tests right after waking were the same or even better. Snoozing also seemed to help them avoid being woken from deep sleep. On the other hand, a 2022 Japanese study of ten university students found that snoozing made them feel groggy for longer. So the effect may depend on the person.

Hitting the snooze button is widely regarded as a bad habit that fragments sleep and leaves people groggy, yet recent evidence complicates that view. In a study from Stockholm University published online in 2023, a survey of 1,732 people showed that snoozing was common, especially among younger people and evening types. In a laboratory experiment, 31 habitual snoozers snoozed for 30 minutes on one morning and were woken abruptly on another. Snoozing reduced total sleep by only about six minutes, and performance on cognitive tests immediately after waking was either unchanged or slightly better, with no clear differences in sleepiness, mood or stress hormones.

One possible explanation is that snoozing reduced the chance of being woken directly from deep sleep, which tends to intensify sleep inertia. In contrast, a 2022 Japanese experiment with ten students found that snoozing made the final 20 minutes of sleep lighter and prolonged post-waking grogginess. The Swedish authors themselves noted that their findings apply only to habitual snoozers. Because both experiments were small and measured different outcomes, several thinking tests in one case and simple reaction times and vigor ratings in the other, the question remains unresolved.