University students are less well-rested than 20 years ago: the problem with not seeing sleep as part of learning

Studying late into the night, finishing an assignment in the early hours of the morning or getting through the week by telling yourself that the weekend will make up for lost sleep are all familiar parts of university life. It may seem as though little has changed: previous generations also spent nights surrounded by notes and went through exam periods on less sleep than usual.

However, when data spanning more than two decades are compared, an important difference emerges. Today’s university students feel well-rested far less often than those who were studying at the beginning of the century.

An analysis of nearly 1.6 million university students in the United States, based on surveys collected between 2000 and 2023, shows that the average number of days per week on which young people felt they had slept enough to wake up rested fell from 3.07 to 2.42 days.

The change becomes even clearer when looking at those who experienced that feeling on only two days a week. In 2000, they accounted for approximately 39.5% of students. By 2023, the figure had risen to 59.8%.

In other words, almost six in ten university students reported waking up feeling sufficiently rested on no more than two days out of seven.

The study did not simply ask how many hours students slept

This detail is important for understanding the findings.

The researchers did not ask students whether they slept six, seven or eight hours. The question was much simpler: “On how many of the past seven days did you get enough sleep so that you felt rested when you woke up?”

The answer captures factors that a simple number of hours cannot. Two people may spend the same amount of time in bed and wake up feeling very differently. Sleep continuity, nighttime awakenings, timing, regularity and individual needs can all influence how rested someone feels.

This does not mean that sleep duration is unimportant. For adults, general recommendations advise at least seven hours of sleep on a regular basis. Consistently sleeping below this threshold has been associated with poorer cognitive functioning and a range of health problems.

But the new study focuses on something much more immediate: it is not enough simply to say that you have slept; what matters is how you feel the following day.

The decline did not happen overnight

Another interesting finding emerges when the results are examined year by year.

During the first years analysed, approximately between 2000 and 2008, students’ levels of sufficient rest actually showed a slight improvement. A sustained decline began afterwards and continued until 2019. From that point onwards, the results stabilised, but at considerably worse levels than those recorded at the beginning of the century.

The data therefore do not support reducing the phenomenon simply to an effect of the pandemic.

Nor do they point to a single cause. The researchers discuss possible cultural and technological changes and note the parallel rise in mental health problems among young people, although this study was not designed to demonstrate that smartphones, social media or any other specific factor are responsible for the decline observed.

A combination of factors is likely to be involved: irregular schedules, combining work and study, nightlife, digital devices, stress or psychological difficulties. Sleep and mental health also have a two-way relationship: poor sleep can sometimes be associated with greater vulnerability to problems such as anxiety or depression, while these same conditions can in turn make it more difficult to sleep well.

Sleep is not time taken away from studying

There is also a contradiction deeply embedded in academic life: when time is short, sleep is often one of the first things to be sacrificed in an attempt to become more productive and gain a few extra hours in the day.

The problem is that learning depends on processes that continue even after the books are closed.

During sleep, processes related to memory consolidation and cognitive functioning take place. Poor sleep can affect attention, processing speed, the ability to maintain concentration and performance the following day.

Recent research using devices to measure university students’ sleep points in the same direction. A four-year follow-up study found a positive relationship between sleep duration and academic performance throughout university. Another study, which used wrist-worn devices to objectively record sleep patterns, found that students with better academic results showed, among other characteristics, greater sleep efficiency and less variation in their sleep schedules from one night to another.

For now, these are associations and do not allow us to conclude that sleeping a specific number of additional minutes will automatically improve a grade. However, they do challenge a widespread assumption: sacrificing sleep to gain more study time does not necessarily lead to more or better learning.

The problem with living for the weekend

The percentage of students who feel well-rested on only two days a week is particularly striking because it fits a familiar pattern: accumulating tiredness throughout the academic week and hoping to recover once the weekend arrives.

Sleeping longer after several short nights can reduce some of the accumulated sleepiness, but it does not automatically turn five days of insufficient rest into a problem that has been solved.

There is also a paradox in resting more precisely on the days with fewer physical and mental demands, while the days when students need to attend classes, understand new material, make decisions, take part in activities or sit an exam may also be the days when they have less capacity to remain alert.

Regularity matters too. Substantially changing bedtimes and wake-up times between weekdays and weekends can alter the sleep-wake rhythm and make returning to the usual schedule on Monday even more difficult.

Not all students show the same pattern

The large sample size also allowed the researchers to identify differences between groups.

The decline in sufficient rest over the two decades studied was greater among women than among men. Students from racial and ethnic minority groups also showed higher overall levels of insufficient sleep, although the pattern of deterioration over time was similar.

These results do not, by themselves, explain the reasons behind those differences. They do, however, remind us that speaking about “university students” as though they were a homogeneous group can conceal very different realities. Employment conditions, family responsibilities, financial circumstances, physical and mental health, and even the environment in which someone lives can all influence when and how they sleep.

Is sleep also an educational issue?

Perhaps one of the most interesting questions raised by this research is not one that individual students should have to answer alone.

If rest affects the ability to learn, it can also be understood as an issue related to education and the way universities are organised.

The authors suggest measures ranging from greater education about sleep health to reconsidering certain schedules, assignment deadlines or characteristics of residential environments. This does not mean removing individual responsibility or expecting everyone to follow exactly the same routine. Rather, it means moving away from presenting sleep deprivation as an inevitable consequence — or even almost a badge of effort — of university life.

For years, nutrition, physical activity, mental health and stress management have been discussed as important aspects of student wellbeing. Sleep has received considerably less attention despite playing a role every day in something fundamental to any educational institution: the ability to pay attention, remember, reason and learn.

Perhaps the question is not how many more hours a student can stay awake to prepare for an exam, but how much of what they study, and what they are expected to learn the following day, may be compromised when sleep becomes the variable we are always willing to sacrifice.