I was no stranger to late nights and early awakenings during my early undergraduate years. I stretched myself thin on sleep but told myself that all would be well if I got a good night’s sleep the night before an important exam. Little did I know that one night of good sleep after a semester of sleepless nights was like putting a band-aid on a bullet hole.
Sleep hygiene refers to habits and practices that promote restful sleep daily. Just like brushing our teeth every day is important for our dental hygiene, there are small actions that are critical for our sleep hygiene. These habits include maintaining the same sleep schedule, avoiding caffeine late in the day, exercising regularly, and having a dark, cool, and quiet sleep environment. Social jet lag occurs when there is a lack of sleep consistency. Sleep inconsistency is very common among students in higher education because they typically sleep late during the weekdays and wake up early for the dreaded morning classes. Then, most students oversleep on weekends in attempts to make up for the sleep debt.
There is no doubt that proper sleep is critical for our well-being including both our physical and mental health. In addition to this, sleep is associated with many superior cognitive functions including better memory and learning. Therefore, it is no surprise that sleep has been associated with academic performance in school. While a few studies report null effects, most studies looking at the effects of sleep quality and duration on academic performance have linked longer and better-quality sleep with better academic performance such as school grades and study effort. I think I can personally say that I learn much better when I am caught up on sleep.
Contrary to this popular belief, a recent study by Okano et al. suggests that one night of good sleep before an exam may not be enough to improve your test performance the next day. In the study, 88 students in an introductory chemistry course were given Fitbits to measure their sleep quality, duration, and consistency. The researchers then compared this data to the students' performance on quizzes and tests. The researchers found that better quality, longer duration, and greater consistency of sleep correlated with better grades. Not a big surprise. However, when they compared students’ academic performance with their sleep activity the night before an exam, they found that there was no correlation between the sleep obtained a single night before a test and test performance. Rather, they found that sleep quality and duration over the full month before a midterm was a better predictor of test performance.
These results provide support for the importance of sleep throughout the semester as the content is being learned. Many studies emphasize the importance of this type of sleep, termed “content-relevant sleep”, for memory consolidation and learning. Therefore, rather than getting a good night's sleep, the researchers suggest that sleep hygiene throughout the semester is a better predictor of academic performance and can account for up to nearly 25% variation in academic performance. Interestingly, the researchers also found that while one good night's sleep before an exam is not a good predictor of performance the next day, neither is one bad night's sleep before an exam. Therefore, those restless nights before an exam may not be as detrimental as one may have believed
It is important to note that while these results provide quantitative, objective evidence that more consistent, longer duration, and better-quality sleep are related to better academic performance they do not provide support for a causal relationship. That is to say that many other factors could be influencing the relationship observed. For example, better-performing students are more likely to have better sleep hygiene throughout the semester. Similarly, factors such as stress, anxiety, motivation, personality traits, and gender roles can all influence the observed relationship between sleep hygiene and test performance. Furthermore, while Fitbits are relatively reliable for tracking activity, like most devices, they may not be tracking sleep with complete accuracy. Fitbits use cardiac, respiratory, and movement measurements to deduce various characteristics of sleep. It has been found that Fitbit devices tend to accurately estimate the sleep stages, however, they may not have a completely accurate measurement of sleep quality. Therefore, the results from the aforementioned study need to be investigated with more robust equipment.
While getting a good night’s sleep before an exam is likely a good idea, students should focus more on their long-term sleep habits throughout the semester. This includes setting a consistent sleep routine and sticking to it because more likely than not, one night of good sleep is insufficient to account for a semester's worth of poor sleep hygiene. Some common tips recommended for good sleep hygiene include the following:
- Establish a consistent sleep schedule by going to bed and waking up at the same time every day – even on weekends! One night out won’t ruin your sleep hygiene just like one night of not brushing your teeth won’t give you instant cavities.
- Sleep in a cool, dark, and quiet environment for optimal sleep quality. Noise, particularly common in dorms and city centers, can cause many students to wake up at night which can reduce the quality of sleep.
- Make your bedroom a comfort haven. Don’t skimp on a comfortable mattress or a pillowy duvet; it’s a long-term investment in your health and academics.
- Avoid using your phone too close to bedtime.
- Exercise daily even if it is just a “mental health walk” for coffee.
- Avoid excessive caffeine and alcohol intake, especially late in the day.
Entering the last year of my undergraduate degree, I began to appreciate my sleep routine a lot more. I found myself going to bed at 9 pm most nights, even if that meant cutting back on some study time. I found a routine that worked for me, and I can say with certainty that I had a lot less trouble concentrating and staying awake in class. I will say that the one downside to my early bedtime was yawning on the dance floor on nights out.
Daniela is a recent B.Sc. graduate from the program of Physiology at McGill. She is very passionate about understanding the human body and how we can all individually adapt our daily lifestyles to improve its functioning.
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