Circadian rhythms in the classroom

Written by: Dr Nicola Davies | Published:
Image: Adobe Stock

Starting the school day at 10am to better suit teenagers’ circadian rhythms is not a practical option. As such, Dr Nicola Davies looks at what we can do within the classroom instead

It is your morning class and you are faced by the all-too-familiar droopy eyes and sleepy yawns. Your students are struggling to focus and however hard you try to engage them, it is difficult to get them to wake up enough to follow the lesson, let alone actively participate in their learning.

We are all guilty of accusing teenagers of being lazy. According to Dr Steven Lockley, an associate professor from Harvard Medical School, “the impact of early school times on adolescents is not understood by most educators”.

He continued: “A common belief is that adolescents are tired, irritable and uncooperative because they choose to stay up too late, or are difficult to wake in the morning because they are lazy.”

However, with so many young people chronically sleep deprived, it is important to start recognising this not as a problem with teenagers, but as a natural part of being a human who is fighting their biology to make it to class. Some people tend to be more active in the morning, whereas others can’t get their brains into gear before midday. Our energy levels and mental alertness are controlled by the “circadian rhythm” – our innate biological clock, which regulates our sleep and waking cycle. Having different circadian rhythms is what makes an early bird and night owl so different.

However, regardless of our circadian rhythm, studies have found that we all have one thing in common – our sleep pattern shifts a few hours later during adolescence. This means that it is harder for teenagers to fall asleep and wake early.

Working with a teenage biological clock

Many studies on circadian rhythms and education have looked at how students’ performance and health is affected by changing the school start time. For example, a study by Kelley et al (2017) found that if teenagers are usually required to be at school by 8:30am, but for a number of years they are allowed to arrive at 10am, sick days decrease and academic performance improves.

What’s more, by changing the start time back to 8:30am, these effects begin to reverse and worsen.
This implies that the best option would be to simply change the start times of schools nationwide and allow students to arrive later. Realistically, however, this often isn’t an option, so we need to explore other possibilities that can fit within the parameters of our current education system.

According to Amanda Livermore, a former teacher from London: “Changing school timings can be impractical and perhaps not necessarily effective. As long as students are getting an adequate number of hours sleep, as per their age requirement, they can perform well in school irrespective of the time.”

So, rather than advocating for the impractical step of shifting school hours, a more practical intervention is to encourage children to go to bed earlier to ensure they get enough sleep.

Sleep education starts at home

Although we can’t choose our natural circadian rhythm, there are steps we can take to retrain our sleep pattern and make it more suited to our schedules. Think of night shift workers – these individuals are required to take steps to ensure their sleep patterns become more nocturnal. Of course, as teachers, we can’t control our students’ bedtime etiquette or tell them to turn off their phones after 10pm, but a more logical first step is to educate parents.

Many parents don’t understand the importance of sleep cycles, or how it affects learning. If possible, schools and teachers should be looking to provide parents with information about promoting healthy sleep routines. For example, according to Helene Emsellem, director of the Center for Sleep and Wake Disorders in the USA, letting somebody (including teenagers) lay in by just 90-minutes on the weekends can disrupt their sleep cycle and perpetuate problems with daytime alertness.

Practical methods for in the classroom

So, now that we’ve looked at some external factors, let’s get down to the nitty gritty. When your students sluggishly file into your classroom, how can you try and improve alertness and thus the learning environment?

Dr David Sousa is an international education consultant who is considered an expert in brain function and learning strategies. He suggests that if you want to help stimulate children’s brains, there are two major changes that you can make to your classroom.

First, individuals who are experiencing some form of sleep deficit have high levels of melatonin – the hormone that regulates sleep and wakefulness. One simple way of decreasing production of this chemical is to make sure the environment is brightly lit – open the curtains or blinds and ensure the room has plenty of natural lighting to help make your students feel more alert.

Second, Dr Sousa suggests that by acknowledging that teachers will experience an early-afternoon lull in energy levels, while their adolescent students are still on their way to reaching peak alertness, teachers can try and tailor activities to match this. If you have a group project or computer-based task for your students to get on with, this will not only allow them to make the most of their energy but will also allow you to manage your waning energy levels better.

So, although there are many other strategies of varying success, there are two areas we need to focus on: environment and time management. The environment can include factors such as lighting, temperature, and classroom decor. Time management involves carefully scheduling and managing students’ natural alertness cycles.

Methods for managing your students’ time and alertness are particularly useful, as morning classes will naturally be less effective than afternoon classes. By acknowledging this and making use of different teaching styles, teachers can maximise the effectiveness of their classes.

For example, if you have a group of teenagers for one morning and one afternoon class per week, it may be useful to use the morning class for shorter, less intensive tasks and use afternoon classes for tasks that require more focus and attention.

By carefully planning your tasks and accounting for student alertness, you’re making the most of the time you have and creating a much richer learning environment for your students. Plus, these simple steps don’t require as much time and effort as petitioning for later school hours or sending out leaflets educating parents about weekend bedtime routines.

The take-home message

It may be easier, in the short-term, to give in to students and keep the blinds closed or keep the room a little warmer, but by putting some thought into the classroom environment and your lesson plans, your students will be able to make the most of their natural energy peaks.

It is easy to see teenagers as lazy and “problematic”, but by taking the time to understand their needs, teachers can make schooling more effective and productive, while also making it easier and less stressful for both themselves and their students.

In the beginning it may be difficult, but by introducing small changes, you will soon be encouraged by the positive differences seen in your classroom – most notably, happier students who have a greater mental capacity to process and learn.

Further information

  • Is 8:30am still too early to start school? A 10am school start time improves health and performance of students aged 13-16, Kelley, Lockley, Kelley & Evans, Frontiers in Human Neuroscience, December 2017:
  • Circadian rhythms are powerful, but people can change their sleep-wake cycle, Carolyn Butler, Washington Post, 2010:
  • Impact of Circadian Rhythms on Schools and Classrooms, Dr David Sousa, October 2011:
  • It’s all a question of timetabling..., SecEd, July 2013:


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