Frame 1 - The Importance of Sleep


MATH2237 Data Visualisation with R

Assignment 3 - Storyboard

The Importance of Sleep

Andy Chen s3935474

Frame 2 - Introduction

Did you know?! We spend about one-third of our life sleeping (Aminoff et al., 2011)! Sleep is essential for the normal functioning of people. Sleep plays an important role in a range of critical biological functions including tissue repair and regeneration, cognitive and memory consolidation, emotional regulation, immune system support and metabolism.

The Sleep Health Foundation of Australia recommends adults aged 18-64 to get 7-9 hours of sleep per night (Sleep Health Foundation, 2024). Consistently undersleeping below the recommended range can have significant health implications into the future. As someone who has personally struggled with maintaining a healthy sleep schedule throughout my entire life, I hope that this storyboard can provide me with insights into ways I can improve my sleep and hopefully you, the reader, can learn ways to improve too!

We will start with a broad overview by looking at sleep data from around the world, then visualising differences in sleep across different age groups and genders, then look at the health implications of poor sleep and finish off by analysing my own self-collected sleep data.

Frame 3 - Global Sleep Data

  • Looking at sleeping data from around the world sourced from (Coutrot et al., 2022), we can see that the majority of participating countries fall within the recommended 7-9 hours of sleep per night. There is a clear trend that European countries on average get the most sleep with Albania getting the most sleep at 7 hours and 31 minutes, while Asian countries on average get the least sleep with Japan getting the least sleep at 6 hours and 38 minutes. Looking closer to home in Australia, we are decently situated around the middle with a Mean Sleep Duration of around 7 hours and 30 minutes.

  • Next, we will further explore the reasons behind why some countries from different continents may get different amounts of sleep by mapping Mean Sleep Duration against GDP per Capita.

Frame 4 - Global Sleep Data with GDP

  • This plot is interactive - feel free to hover over countries for details! GDP per Capita has been normalised to better help identify trends. Data sourced from (Coutrot et al., 2022).

  • This graph looks at whether a relationship exists between how much countries sleep on average and how productive they are. However, no clear strong relationship can be seen between a country from a particular continent and how productive they are. There is the possibility of a weak negative linear relationship between sleep duration and GDP per capita, meaning that most countries in the world are able to achieve either high GDP with low sleep or low GDP with high sleep or moderate GDP with moderate sleep. Looking at Australia, we are quite close to the middle of the plot with a moderate amount of sleep and moderate amount of productivity!

  • For our next visualisation, we will look at sleep durations of different continents divided across different age groups and gender.

Frame 5 - Global Sleep across Age Groups and Gender

  • This visualisation plots the Mean Sleep Duration across different age groups for males and females faceted by continent. Data sourced from (Coutrot et al., 2022).

  • Interestingly females consistently got more sleep than males across different continents and age groups. This is likely due to hormonal differences that can cause sleep disruptions in females resulting in more time spent in bed (Burgard & Ailshire, 2013). Furthermore, all continents (except Africa) exhibit a U-shape across age groups, with 41-50 year olds getting the least sleep. A number of reasons can be attributed to this trend including a decline in hormone regulation associated with aging and exacerbation of stress experienced at work and home (Maggio et al., 2013). Across most continents older adults aged 65+ exhibit longer mean sleep durations likely because of lifestyle changes due to retirement that enables flexible sleep schedules or health conditions associated with aging that cause sleep disruptions (Li et al., 2019). For my age range of 18-25 for Australian males they got an average of 7 hours and 19 minutes of sleep.

  • For our next visualisation, we will look at the health implications of both not getting enough sleep and getting too much sleep.

Frame 6 - Health Implications of Poor Sleep

  • This visualisation plots the risk ratios for chronic conditions and their corresponding 95% Confidence Interval with differing sleep lengths consisting of undersleeping, normal sleep and oversleeping. A risk ratio of 1 reflects the baseline risk associated with normal sleep while numbers above 1 indicate an increased risk. Data Sourced from (Australian Institute of Health and Welfare, 2021).

  • We can see that undersleeping is associated with an increased risk of multiple health conditions including coronary heart disease (CHD), cardiovascular disease (CVD), diabetes, hypertension, obesity and stroke. This is due to the fact that sleep deprivation is associated with increased inflammation of the body and additionally disturbs normal immunological system function (Léger, et al. 2014). Interestingly, this visualisation shows how oversleeping can also result in an increased risk of developing a chronic health condition with similar risk ratios to that of undersleeping, which can be indicative of a sleeping disorder.

  • For the remainder of this storyboard, we will explore and analyse self-collected data about the way I sleep and compare with what we have learnt about how other people sleep from around the world.

Frame 7 - Own Sleep Data Sleep Duration

  • This visualisation tracks my sleep duration each night from 20 May - 3 June 2025. Data collected using Sleep Cycle App and available for viewing under References (Chen, 2025).

  • Analysing my own sleep data, I had an overall average sleep duration of 5 hours and 59 minutes during this two week period which is under the recommended 7-9 hours and below the average of 7 hours and 19 minutes for my age range of 18-25 for Australian males as seen on Frame 5. I was able to reach the recommended 7-9 hours of sleep four out of fifteen nights and in the remaining 11 nights I underslept, with my lowest duration of sleep being just under 3 hours on June 2nd! It is clear that my sleep durations can be quite erratic and I have a large tendency to undersleep, which has real implications of developing chronic conditions in the future as seen previously on Frame 6.

  • Next, we will conduct a further break down of my sleep durations into the four different sleep stages for each night.

Frame 8 - Own Sleep Data Sleep Stages

  • This visualisation breaks down my sleep duration into the four different sleep stages which can be described as (Patel et al., 2024):
    • Awake: stage of being awake and alert. Should last 5-10 minutes.
    • Light: initial stages of sleep that is easy to wake from. Should last up to 25 minutes.
    • Deep: deeper stage of sleep that is more difficult to wake up from. During this stage the body begins repair and regeneration of body tissue. Should last 30-60 minutes.
    • REM (Dream): stage characterised by rapid eye movements. During this stage there is increased brain activity giving rise to vivid dreaming and memory consolidation. Should go through on average 4-6 REM cycles with the first cycle lasting 10 minutes and final cycle lasting up to 60 minutes.
  • Data collected using Sleep Cycle App (Chen, 2025).

  • It is clear that I spend far too long during the Light sleep stage where I spend an average of 251 minutes, far greater than the recommended 25 minutes! This luckily has not significantly impacted my ability to move onto the Deep sleep stage because I’m actually able to have decent Deep sleep with an average of 49 minutes, which is within the recommended range of 30-60 minutes. Finally, when I move onto the REM stage I get an average of 58 minutes which is within the recommended range of below 60 minutes.

Frame 9 - Conclusion

Sleep is a careful balancing act that requires great discipline to achieve just the right amount of sleep, you can’t have too little and you can’t have too much. Insights that we gained from looking at global sleep data we found that European countries get the most sleep while Asian countries get the least sleep. This is supported by current literature that says Asian cultures tend to undersleep as they emphasize work and academic performance (Kuula et al., 2019). There is a weak negative relationship between countries from different continents getting different sleep durations and their productivity. Furthermore, undersleeping and oversleeping can have devastating implications on one’s health that can result in the development of chronic cardiovascular disease, coronary heart disease, diabetes, hypertension, obesity or stroke.

The main insights I was able to take away about my own sleep was that I have the tendancy to undersleep and I spend far too long in the Light sleep stage. Upon reflection this is likely due to the disruption of melatonin hormone regulation by blue light emitted by screens. Improvements that I need to incorporate into my lifestyle include maintaining discipline and sticking to a consistent sleep schedule, limiting my screen time and cutting down on my caffeine intake before bed.

In the future I’m extremely interested to conduct further in-depth sleep studies with more accurate measuring devices including EEGs to measure brain activity and spirometers to measure respiration! Thank you for reading!

Frame 10 - References

References