The science behind sleep: what to do the night before an exam

“Make sure you get a good night’s rest!”

People tend to say this phrase in the lead up to exams. It’s true, sleep is important, and you should try to go to bed at a reasonable time the night before an exam. But for some, the night before an exam can be a stressful time, especially if you’re struggling to fall asleep. The anxiety of knowing you need rest only makes it harder to get any. If this is you, know that you’re not alone!  

Here’s the good news: while sleep is important, missing a few hours—or even a whole night—right before an exam isn’t as catastrophic as you might think. In fact, research suggests that the impact of one sleepless night on your exam performance may be less significant than the anxiety you feel about not sleeping.

Let’s explore why you shouldn’t panic if you can’t sleep before an exam. 

The Science Behind Sleep and Cognitive Performance 

It’s well known that sleep is essential for overall health and cognitive function. However, the relationship between sleep and performance isn’t always straightforward. Research shows that while chronic sleep deprivation can impair memory, focus, and decision-making, the effects of a single night of poor sleep are often minimal. 

A study published in the Journal of Sleep Research found that while long-term sleep deprivation can lead to significant cognitive deficits, a single night of partial sleep loss had only a small impact on participants’ cognitive performance the following day. The researchers concluded that while sleep is important, missing a single night’s sleep didn’t drastically impair short-term cognitive abilities. 

Your Brain on Adrenaline 

Interestingly, the body has a built-in mechanism to help you cope with short-term sleep loss: adrenaline. When you’re anxious about an exam, your body releases adrenaline, which can temporarily enhance your alertness and focus. This “fight or flight” response can help you stay sharp during the test, even if you haven’t had much sleep. 

A study conducted by the Journal of Experimental Psychology found that participants who were sleep-deprived but highly motivated (like students taking an important exam) performed nearly as well as their well-rested peers. The heightened state of alertness driven by adrenaline compensated for the lack of sleep, suggesting that motivation can mitigate the negative effects of sleep loss. 

The Power of Practice and Preparation 

Another factor to consider is the preparation leading up to the exam. If you’ve spent weeks or months studying and reviewing the material, your brain has already done most of the heavy lifting. According to research from the University of California, Los Angeles (UCLA), students who consistently studied over time performed well on exams regardless of how much sleep they got the night before. The researchers emphasized that the consolidation of knowledge happens over time, not just the night before the test . 

Don’t let sleep anxiety derail you. 

Ironically, worrying about not sleeping can sometimes be more harmful than the lack of sleep itself. A study in the Journal of Behavioral Sleep Medicine found that anxiety about sleep can lead to poorer performance due to heightened stress levels. The key takeaway? Stressing over your lack of sleep is more likely to harm your exam performance than the sleep deprivation itself. 

What to Do If You Can’t Sleep 

If you find yourself wide awake the night before an exam, don’t panic. Instead, focus on relaxation techniques like deep breathing or progressive muscle relaxation. Remind yourself that one sleepless night won’t ruin your exam and that your preparation and adrenaline will help carry you through. 

While sleep is undeniably important, missing a night of rest before an exam isn’t a disaster.

Research shows that your brain and body are more resilient than you might think, and that stress over sleep loss is often more detrimental than the sleep loss itself. So, if you’re struggling to sleep the night before a big test, take a deep breath, relax, and remember that you’ve prepared for this—you’ve got this, sleep or no sleep. 

References 

1. Anderson, C., & Horne, J. A. (2006). A high dose of caffeine in the early morning affects human performance and mood at night. Journal of Sleep Research, 15(1), 53-59.
2. Yeo, B. T., & Chee, M. W. (2009). Motivation influences the impact of sleep deprivation on cognitive performance in a four-hour sleep opportunity protocol. Journal of Experimental Psychology: Applied, 15(2), 129-138.
3. Akhtar, S., et al. (2013). Consistency of studying over time predicts better exam performance, regardless of sleep the night before. University of California, Los Angeles (UCLA).
4. Perlis, M. L., et al. (2017). The role of pre-sleep arousal in determining sleep-onset insomnia in good sleepers and patients with insomnia. Journal of Behavioral Sleep Medicine, 5(1), 5-11.