The impact of sleep on academic performance

For decades, the dreaded all-nighter has been viewed as a fundamental pillar of the college student experience.

Visit any college campus library during exam season and you’ll most likely find students prepped to stay up all night glued to their books. At least one library or study hall stays open on campus 24/7, accommodating scores of students who stay up all night to cram in revision for upcoming exams.

Most students probably know that depriving themselves from sleep is bad, but nonetheless they’re willing to sacrifice sleep and as a consequence, health, telling themselves it’s just for a short time and they can soon start sleeping 12-hours a day once the semester draws to a close.

But research shows that sleep is extremely important, not just during finals week but throughout the entire semester. College students are known for slapdash sleeping habits, but these patterns could be detrimentally impacting your performance, and it’s time to nip them in the bud.

Erratic sleep 

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But besides pulling all-nighters, many college students generally don’t know what it means to have a good sleeping routine. Due to class schedules that differ on a daily basis, part-time jobs, extra-curricular and social activities, students adapt to irregular sleep cycles that can seriously impact their academic performance as well as mental and physical health.

They tend to ‘make up’ for the lack of sleep by laying in bed on weekends or days off, but this just makes the irregular cycle even worse.

A study by Brigham and Women’s Hospital shows how a regular bed time has a significant impact on sleep, not just the number of hours slept. The research measured sleep and circadian rhythms as well as the association to academic performance among college students.

Researchers studied 61 full-time undergraduate students from Harvard College over 30 days. Using sleep diaries, they were able to quantify sleep regularity using the SRI (sleep regularity index).

Then, the relationship between the SRI, sleep duration, distribution of sleep across the day, and one semester’s academic performance was examined by the researchers.

“Our results indicate that going to sleep and waking up at approximately the same time is as important as the number of hours one sleeps,” stated Andrew J. K. Phillips, PhD, Biophysicist at the Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, and lead author on the paper. “Sleep regularity is a potentially important and modifiable factor independent from sleep duration.”

The research found that students who had more regular sleep patterns had better average school grades.

When it came to the average sleep duration, they actually found no significant difference between students with irregular sleep patterns and most regular sleepers.

This goes to show that it’s not always the hours of sleep you’re getting but rather the fact you’re not sleeping regularly, that can affect your performance.

Tick-Tock

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The study shows that the circadian clock, commonly known as the body clock, was almost three hours later in students with irregular sleeping patterns.

“For the students whose sleep and wake times were inconsistent, classes and exams that were scheduled for 9am were therefore occurring at 6am according to their body clock, at a time when performance is impaired. Ironically, they didn’t save any time because in the end they slept just as much as those on a more regular schedule,” stated Charles A. Czeisler, PhD, MD, Director of the Sleep Health Institute at Brigham and Women’s Hospital, and senior author of the paper.

Also, melatonin was released 2.6 hours later among students with irregular sleeping patterns than those for whom sleep came more regularly. The timing of this melatonin release allowed researches to assess the timing of circadian rhythms.

“Using a mathematical model of the circadian clock, we were able to demonstrate that the difference in circadian timing between students with the most irregular sleep patterns and students with regular sleep patterns was consistent with their different patterns of daily light exposure,” stated Phillips.

“In particular, regular sleepers got significantly higher light levels during the daytime, and significantly lower light levels at night than irregular sleepers who slept more during daytime hours and less during nighttime hours.”

The circadian clock is sensitive and takes time to adjust to changes in schedule. This is what causes jet lag and difficulties in adjusting to a new bed time.

Another significant factor that contributes to the circadian clock is patterns of light exposure. Your body clock gets used to regular light exposure, so when it’s exposed to different light exposure patterns at different times of the week, it tends to fall out of whack.

Irregular sleepers, who frequently changed the pattern of when they slept and consequently their pattern of light-dark exposure, experienced misalignment between the circadian system and the sleep-wake cycle.

This led researchers to conclude that light-based interventions may be effective in improving sleep regularity. This means increased exposure to light during the daytime and less exposure to electronic light-emitting devices (your phone, your iPad, or your computer) right before bed.

Staring at your phone right before bed isn’t a good idea for a good night’s sleep. Source: Shutterstock

In summary, the study found that irregular patterns of sleep and wakefulness correlated with lower GPA, delayed sleep/wake timing, and delayed release of melatonin – the hormone that promotes sleep.

So, avoid using your phone right before bed as it can negatively affect your sleep. Also, try to go to bed and wake up at the same time every day to avoid messing up your body’s internal clock.

Avoid sleeping during the day to make up for lack of sleep at night, since this means less exposure to natural light which is important for good sleep.

Not enough sleep

Via Giphy

Although the above study found that bad sleeping patterns contribute to poor academic performance, there have been other studies on the effects of sleep deprivation as well.

A 2001 study by William E Kelly, Kathryn E Kelly and Robert C Clanton found that sleep deprivation affects students’ ability to perform well in class in a significant way.

Their research found that people who slept for nine hours or more in a 24-hour period had much higher GPAs than those who slept for less than six hours in the same time period.

Also, students who slept for less than six hours showed signs of anxiety, neurotic feelings, lack of creativity, and more prone to hallucination.

Memory Loss

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So how exactly do poor sleeping habits and sleep deprivation affect students’ academic performance? Well, it’s not just about waking up late and missing a class, nor that they’re too tired to pay attention in lecture…

Many studies have shown that sleep is imperative to memory consolidation and cognition.

During ‘slow wave sleep’, which is one of the cycles the brain goes through during sleep, the brain replays information learnt while awake.

This leads to memory consolidation, in which information is stored in the long-term memory. This means that if you don’t get enough sleep, your brain doesn’t have enough time to properly run through this cycle, leaving you unable to retain the information picked up the day before.

So if you’re busy cramming and not sleeping, the important information you learnt and thought you had memorized basically slips out of your brain, and you’ll have trouble recalling them the next day.

Good sleep, good grades

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The truth is, pulling all-nighters and maintaining bad sleeping habits will be detrimental to your health. Not getting at least seven to eight hours’ sleep a night on a regular basis has been shown to increase your risk of getting diseases like diabetes, while also promoting weight gain and lower immune systems.

It might just be the cause of the freshman fifteen – a stage that sees many students gain weight during their first year of study.

Most students know that it’s not good for them, but continue to burn the midnight oil and sleeping at odd hours, sacrificing health on the unstable promise of good grades.

Students who don’t put sleep high up in their priorities aren’t actually doing themselves any favours. And as results day looms, they could very well find their sacrifice has been for nothing.

So students: start maintaining good sleeping habits and you’ll find yourself more alert in class and able to retain information. You might find yourself getting better grades and feeling less anxious as a result. Plus, your health and weight is far less likely to suffer!

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