Sleep Quality

We spend about 1/3rd of our life sleeping or trying to do so (Aminoff et al., 2011). That is quite a lot of time if you think about it. And since we sleep for such a big part of our lives, ProFit thinks it is super important to invest in good sleep. Why wouldn’t you make the best out of something you do so much? In this article we are going to take a look at sleep and, more specifically, what you can do to improve yours!

Many factors play a role in sleep quality. There are biological factors and there are behavioral factors. Biological factors are for example your circadian rhythm or the amount of cortisol in your blood. Behavioral factors are, for example, what time someone decides to go to bed or the amount of coffee or alcohol you drink.

A factor that negatively affects the sleep of modern academics is screen time. Lectures have powerpoints or are online. Articles we have to read. Papers we have to write. Summaries we make or study. And in our breaks? We check social media on our smartphones or watch some youtube videos. They are all seen via screens. Screens produce blue light, which more than any other colour, messes with the body’s ability to produce melatonin. A hormone we need to fall asleep.

Sleep quality in itself influences other progresses like performance. For example, a study performed among medical students showed that those who noted subjective bad sleep quality (PSQI) was associated with lower grades (Ahrberg et al., 2012). In addition, students who experienced high levels of stress prior to their exams performed badly on those exams (see figure 1). The percentage of students that experienced worse sleep quality pre-exam was greater (59%) compared to the rest of the semester (29%) or post-exam (8%). The study goes on to suggest a close relationship between stress and sleep quality

Fig. 1: correlation of stress and subjective sleep quality (PSQI) on academic performance (grades 1-5, with 1 being the highest score possible).

Thus far we have shown some examples of factors that play a role in sleep quality and how sleep quality influences academic performance. So, how to improve your own sleep quality? One way to do this is to improve your sleep habits, also known by the term ‘sleep hygiene’. To underline the importance of this so-called sleep hygiene, the American Center for Disease Control and Prevention (CDC) even has a webpage dedicated to tips and tricks to improve your sleep hygiene (CDC, 2017). Most likely you know these tricks already – they’re pretty much common sense – but you might have never gotten around to implementing them successfully. The good news is you can train it, like a muscle. Key terms are relaxed and consistency.

The most important ingredient to this sleep hygiene recipe is to make a habit out of these simple tips and apply them to your life, everyday. And what better day to start than today?


Ahrberg K., Dresler M., Niedermaier S., Steiger A., Genzel L. (2012) The interaction between sleep quality and academic performance. J Psychiatr Res. 2012 Dec;46(12):1618-22. doi: 10.1016/j.jpsychires.2012.09.008. Epub 2012 Oct 3.

Aminoff M.J., Boller F., Swaab D.,(2011) We spend about one-third of our life either sleeping or attempting to do so. Handb Clin Neurol. 2011;98:vii. doi: 10.1016/B978-0-444-52006-7.00047-2.

Center for Disease Controle and and Prevention (2017) U.S. Department of Health & Human Services website. Geraadpleegd op 12-01-2022 van  CDC – Sleep Hygiene Tips – Sleep and Sleep Disorders

For further reading material about sleep hygiene: