Sleep and sleepiness
Sleep is something we all need. It is an important contributor for our health and well-being and is also vital for us to be alert and perform effectively. The amount of sleep a person needs varies from person to person – basically we need the amount that is sufficient for us to feel refreshed and perform efficiently. Most adults sleep typically sleep between 6-8h per night, with a recent consensus concluding at least 7h of sleep a night is needed on a regular basis for optimal health (Watson et al., 2015). However, aspects of our lifestyle, such as work hours, commuting, health, family and social responsibilities, can impact our sleep and lead to instances of shortened or disturbed sleep.
When people think about sleep loss, feeling sleepy and the associated consequences, people may think of instances of extreme sleep loss, for example, staying up all night for events, holidays or work etc. However, it is more likely that individuals experience poor or disrupted sleep or shortened sleep due to getting up early/late nights on a more recurrent basis. Although this may feel part of everyday life, this can still result in increased sleepiness and reduced alertness. Sleepiness can impact performance and in certain circumstances have serious consequences, for example, workplace sleepiness can result in injuries, accidents and incidents (Wagstaff & Lie, 2011; Williamson et al., 2011) and driver sleepiness is associated with increased crash risk (Bioulac et al., 2017).
A typical workday following poor sleep
- Waking – If you have had poor, shortened, or disturbed sleep, then it can be harder to get going in the morning. You may find it difficult to wake up, feel groggy, and sometimes even feel ill. This can be particularly worse for people who are evening types or ‘owls’ (compared to morning types or ‘larks’) due to the slightly later running of their body clock meaning they feel less alert in the morning.
- Commuting – Many people may also need to commute to work in the morning, usually during rush hour. If this involves driving, this can be a risky time. Driving requires you to be alert and vigilant, and poor sleep and increased sleepiness can result in decrements in driving performance, including simple and complex tasks, slower reaction times, impaired attention and even loss of conscious awareness behind the wheel (Williamson et al., 2011).
- The morning at work – due to our body clock, alertness naturally increases in the morning, regardless of sleep. Therefore, the morning might feel ok, although perhaps a little slower going. However, as sleep is important for the brain and cognitive function, poor sleep can impact several skills and abilities which would likely be used at work. For example, you may:
- feel sleepy or drowsy,
- struggle to concentrate or to focus,
- find it hard to make decisions,
- struggle to pay attention or attend to new information,
- struggle to generate new ideas, think creatively or problem solve,
- find it harder to communicate your ideas and thoughts effectively,
- find it harder to assess risk,
- find your reaction time slower,
- find your mood is more irritable.
- The afternoon at work – The effects of poor sleep may be more noticeable in the afternoon. Often called the ‘post-lunch dip’, we naturally experience a dip in alertness during the afternoon, again regardless of sleep or lunch. However, this dip is exacerbated by poor sleep; that is if you have had disrupted or shortened sleep, your afternoon dip will be bigger. You may feel sleepier and notice even more of an impact on the cognitive skills mentioned above. Although likely not possible at work, this time (roughly between 1-3pm) would be the perfect time for a short nap! However, strategic caffeine intake at this time also works well to help reduce sleepiness.
- Commute home – Following the afternoon dip, our alertness naturally starts to increase again from late afternoon to early evening. Just be aware of how you feel in terms of sleepiness before getting behind the wheel of a car to drive and do not drive if you feel sleepy. Caffeine and napping strategies are the most effective countermeasures for driver sleepiness. It is worth bearing in mind that popular strategies such as opening a window, listening to music/radio or taking a break will not reduce sleepiness for extended periods of time (Horne & Reyner 1996; Schwarz et al. 2012).
- Evening – You will likely experience less sleepiness in the early evening due to the natural increase in alertness, but sleepiness will increase as the evening progresses. It is important to you give yourself time to wind down, relax and complete your bedtime routine to try to help you sleep well. A bedtime routine is a good thing to try and do any, and every night.
If you work outside of a 9-5 job / are a shift worker, then poor sleep may result in even more pronounced sleepiness. This can be due to working at times when the body is usually asleep or trying to sleep at times when the body is usually awake, which can be difficult. This can also include working early shifts and waking earlier than you naturally would, all of which would impact sleep and sleepiness.
General sleep hygiene tips
Although sleep is something we all experience, there are individual differences, for example the amount of sleep someone needs to feel alert and refreshed. However, establishing a bedtime routine is something that can be beneficial to everyone, and can help relax and prepare you for sleep. Some general tips are:
- Try to keep a regular sleep/wake schedule.
- Avoid stimulants close to bedtime.
- Make sure the room you sleep in is dark and quiet.
- Avoid screen/electronic use in bed and try to reduce before bedtime.
- Don’t use or rely on alcohol to sleep.
- Allow time to relax and unwind.
Finally, if you are experiencing poor, shortened or disturbed sleep on a regular basis, or feel excessively sleepy during the day, it is important that you speak to your GP.
The Sleep Charity: https://thesleepcharity.org.uk/
NHS sleep advice: https://www.nhs.uk/live-well/sleep-and-tiredness/how-to-get-to-sleep/
- Bioulac, S., Micoulaud Franchi, J. A., Arnaud, M., Sagaspe, P., Moore, N., Salvo, F., & Philip, P. (2017). Risk of motor vehicle accidents related to sleepiness at the wheel: A systematic review and meta-analysis. Sleep, 40(10). https://doi.org/10.1093/sleep/zsx134
- Horne, J. A., & Reyner, L. A. (1996). Counteracting driver sleepiness: Effects of napping, caffeine and placebo. Psychophysiology, 33(3), 306–309. https://doi.org/10.1111/j.1469-8986.1996.tb00428.x
- Schwarz, J. F. A., Ingre, M., Fors, C., Anund, A., Kecklund, G., Taillard, J., Philip, P., & Åkerstedt, T. (2012). In-car countermeasures open window and music revisited on the real road: popular but hardly effective against driver sleepiness. Journal of Sleep Research, 21(5), 595–599. https://doi.org/10.1111/j.1365-2869.2012.01009.x
- Wagstaff, A. S., & Lie, J. A. S. (2011). Shift and night work and long working hours – A systematic review of safety implications. Scandinavian Journal of Work, Environment & Health, 37(3), 173–185. https://doi.org/10.5271/sjweh.3146
- Watson, N. F., Badr, M. S., Belenky, G., Bliwise, D. L., Buxton, O. M., Buysse, D., Dinges, D. F., Gangwisch, J., Grandner, M. A., Kushida, C., Malhotra, R. K., Martin, J. L., Patel, S. R., Quan, S. F., Tasali, E., Twery, M., Croft, J. B., Maher, E., Barrett, J. A., … Heald, J. L. (2015). Joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society on the recommended amount of sleep for a healthy adult: methodology and discussion. Journal of Clinical Sleep Medicine, 11(8), 931–952. https://doi.org/10.5664/jcsm.4950
- Williamson, A., Lombardi, D. A., Folkard, S., Stutts, J., Courtney, T. K., & Connor, J. L. (2011). The link between fatigue and safety. Accident Analysis & Prevention, 43(2), 498–515. https://doi.org/10.1016/j.aap.2009.11.011
Fran Pilkington-Cheney’s Bio
Fran Pilkington-Cheney is a researcher at the Transport Safety Research Centre (TSRC) at Loughborough University. Her research focuses on sleepiness and fatigue within safety critical tasks, for example during shift work and driving. Fran has a BSc in Psychology and has recently submitted her PhD which explores the management of sleepiness, particularly within the applied context of bus driving. Fran is a member of the British Sleep Society (BSS) and European Sleep Research Society (ESRS and in 2020 was elected to join the ESRS Early Career Researcher Network Committee.