Is It Okay to Sleep More After a Short Night? Findings from a Study Tracking 85,000 People

Analysis of Sleep Data from 85,618 Participants
Recovery Sleep After Sleep Restriction Is Essential

A new study has found that "recovery sleep," in which a person sleeps about one hour longer than usual the day after a night of insufficient sleep, may help reduce the risk of premature death. However, both the research team and external experts emphasized that these results do not mean "it's fine to routinely cut back on sleep as long as you make it up later."

On May 19 (local time), a research team led by Xiaoyu Li, a sleep researcher at Tsinghua University in China, published a study in the international journal Nature Communications, analyzing sleep data from 85,618 participants in the UK Biobank. Based on 574,230 days of sleep records measured using wrist-worn accelerometers, the researchers examined the association between an increase in sleep duration the night after sleep restriction and long-term mortality rates.

The research team reported that, after an average follow-up period of 8 years, participants who did not engage in recovery sleep following sleep restriction had a higher risk of all-cause mortality. The photo is unrelated to the specific content of the article. Pixabay

The average age of study participants was 61.8 years, and the overall average sleep duration was 6.4 hours per day. The researchers estimated each individual’s "required sleep duration" based on the average sleep duration of people of the same age and gender group. Cases where participants slept significantly less than this value were classified as "sleep restriction." If a participant slept longer than their required sleep duration the night after a sleep-restricted night, this was defined as "sleep rebound" or "recovery sleep."

According to the analysis, 72.1% of all participants belonged to the "regular sleep group," showing no clear signs of sleep restriction. The remainder were divided into four groups depending on whether they had recovery sleep following sleep restriction. Of the participants, 9.0% experienced sleep restriction but did not have recovery sleep, while 8.5% exhibited recovery sleep after sleep restriction. Groups that experienced more severe sleep restriction were also subdivided based on the presence or absence of recovery sleep.

'Recovery Sleep' After a Night of Sleep Deprivation... Potential to Lower Eight-Year Mortality Risk

The research team announced that, after an average follow-up period of eight years, participants who did not engage in recovery sleep following sleep restriction showed a higher risk of all-cause mortality. This association was especially pronounced among individuals who normally had shorter sleep durations. In contrast, those who slept extra hours the day after a short night did not show a clear increase in mortality risk compared to the regular sleep group.

This study is characterized not only by examining the so-called "weekend catch-up sleep," where sleep is compensated all at once on weekends, but also by analyzing how daily sleep duration decreases and recovers in real-life settings. The photo is unrelated to the specific content of the article. Pixabay

The research team explained that these results "suggest that recovery sleep following sleep deprivation may buffer against the negative effects of previous sleep loss." They also reported similar trends in an additional analysis using accelerometer-based sleep data from 4,586 participants in the U.S. National Health and Nutrition Examination Survey (NHANES).

The distinctive feature of this study is that it did not focus solely on the so-called "weekend catch-up sleep," where people compensate for lost sleep all at once over the weekend, but rather analyzed how daily sleep duration decreases and recovers in real-life settings. According to the original paper, sleep restriction occurred more frequently on weekdays, and recovery sleep was also more common during weekdays than on weekends. However, the research team noted that, as this was an observational study, it cannot be concluded that sleep deprivation directly causes death or that recovery sleep directly prevents it. The Nature Communications paper also specified its limitations, stating that "causal relationships cannot be inferred due to the observational study design."

There have been calls for a more cautious interpretation of these findings. Jean-Philippe Chaput, a sleep expert at the University of Ottawa in Canada, told the science publication Science that, "The concept that recovery sleep can partially compensate for acute sleep deprivation aligns with biological understanding," but warned that this should not be interpreted as a license to repeatedly cut back on sleep during the week. The research team also concluded, "Especially for individuals who usually have short sleep durations, it is helpful to avoid sleep restriction, and if unavoidable, to get recovery sleep as soon as possible."

This content was produced with the assistance of AI translation services.