Issue #68 – March 2021
Welcome to Focus on Fatigue!
While some people swear by the rejuvenating impact of a power nap, others maintain that napping leaves them feeling worse off than before. In this month’s Focus on Fatigue, we will take a look at the ins and outs of napping on the job and how to make your nap count.
The FRMS Team
InterDynamics Pty Ltd
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Tel +61 7 3229 8300
Views expressed in articles and links provided are those of the individual authors, and do not necessarily represent the views of InterDynamics (except where directly attributed).
Napping for Success
The US Army recently released a new physical training manual, rebranded as the FM7-22 Holistic Health and Fitness manual, in which it promotes what the New York Times has coined as “strategic and aggressive napping”. The manual includes the following guidelines:
“When regular nighttime sleep is not possible due to mission requirements, Soldiers can use short, infrequent naps to restore wakefulness and promote performance. When routinely available sleep time is difficult to predict, Soldiers might take the longest nap possible as frequently as time is available”.
Whilst napping on the job is by no means a new phenomenon, official endorsement by organisations has grown in recent years. The healthcare industry has seen an increase in programs supporting workplace napping, and many companies, such as Google and Huffington Post, now have sleep pods available for use in their offices.
Research shows that a nap can reduce sleepiness, improve alertness, mood, performance and reaction time. For those working extended hours and shift work, the use of strategic naps can be an important, and sometimes critical, part of fatigue management. Here’s how to make your nap count.
Napping at work is most beneficial when it is a recognised part of an organisation’s fatigue management plan and appropriate facilities and support are provided.
Unlike a doze, a strategic nap is planned in advance. The timing and duration of the nap is determined by weighing the benefits of the nap against the potential negative consequences. A strategic nap also allows workers to coordinate with their colleagues and possibly arrange for any essential work activities to be covered while the planned nap is taking place. All of this helps workers to manage their fatigue effectively, and thus reduces risk.
Length of Nap
Recommendations on the ideal power nap length vary slightly, but are generally considered to be between 10 minutes and less than 30 minutes. Naps as short as 10 minutes have been shown to improve alertness and performance. Naps greater than 30 minutes, where an individual enters deeper sleep, increase the potential effects of sleep inertia (the grogginess felt upon awakening) and may require extra time after waking before returning to safety critical tasks. However, if circumstances allow, longer naps involving REM sleep have been shown to provide performance benefits for an extended period of time, as well as additional benefits such as boosting problem solving and creativity.
Timing of Nap
Napping is most likely to be successful if timed when your body’s drive to sleep is high. The body’s circadian rhythm promotes sleep during the night, with the strongest urge to sleep around 2 to 6am. There is also a secondary dip in alertness in the afternoon around 1 to 4pm, hence the popularity of an afternoon siesta in some cultures. By timing your nap for these circadian lows, it increases the likelihood of obtaining good quality sleep. However, waking during circadian lows can also increase the effects of sleep inertia. If you have a significant sleep debt and your drive to sleep is high, then sleep may also be successfully obtained at other times.
How about a Coffee Nap?
Having a coffee followed by a short sleep is more effective, in increasing cognitive performance and reducing sleepiness, than a nap alone. Coffee prior to a nap can also reduce the impact of sleep inertia on waking. The two work together to give that extra boost to get you through.
Downsides of Napping
There are two potential negative effects of napping that should be considered when deciding if, when and how long to nap for. These are: sleep inertia and the potential disruption to subsequent sleep.
Sleep Inertia – This is the grogginess and disorientation we feel when first waking from a nap. While under the effects of sleep inertia, task performance can be worse than if the person had not napped at all. Depending on the length of the nap, timing of the nap, stage of sleep you wake from and your level of sleep deprivation, sleep inertia can last from a few minutes up to an hour or longer. However, the effects greatly dissipate within 15-30 minutes in most cases.
If a nap is interrupted by an emergency requiring a quick response with a high level of performance, that person may end up responding to the emergency while suffering the effects of sleep inertia. Therefore, if this possibility exists, it will be necessary to weigh up the benefits of improved alertness and performance during regular work, with the likelihood of an emergency occurring during the period when sleep inertia is an issue.
Prior sleep deprivation exacerbates sleep inertia (the body just doesn’t want to wake up yet!). Therefore, staying ahead of sleep debt is one way to help reduce sleep inertia.
Disruption to subsequent sleep – Recovery sleep between shifts is essential to ensure that workers are ready for their next shift. Napping for long periods, or later in a shift, can disrupt the quantity and quality of subsequent sleep. This should be considered when timing naps.
- Centofani, S., Banks, S., Coussens, S., et al. (2020) A pilot study investigating the impact of a caffeine-nap on alertness during a simulated night shift. Chronobiology International. 37(9-10), 1469-1473. http://doi.org/10.1080/07420528.2020.1804922
- Geiger-Brown, J., Sagherian, K., Zhu, S., et al. (2016). CE: Original Research: Napping on the Night Shift: A Two-Hospital Implementation Project. The American journal of nursing, 116(5), 26–33. https://doi.org/10.1097/01.NAJ.0000482953.88608.80
- Hilditch, C. J., & McHill, A. W. (2019). Sleep inertia: current insights. Nature and science of sleep, 11, 155–165. https://doi.org/10.2147/NSS.S188911
- Patterson, P. D., Weaver, M. D., Guyette, F. X., & Martin-Gill, C. (2020). Should public safety shift workers be allowed to nap while on duty?. American journal of industrial medicine, 63(10), 843–850. https://doi.org/10.1002/ajim.23164
- Rosekind, M. R., Smith, R. M., Miller, D. L., et al. (1995) Alertness management: Strategic naps in operational settings. Journal of Sleep Research, 4, 62-66.
- Sadeghniiat-Haghighi, K., & Yazdi, Z. (2015). Fatigue management in the workplace. Industrial psychiatry journal, 24(1), 12–17. https://doi.org/10.4103/0972-6748.160915
- Signal, T. L., Gander, P. H., Anderson, H. and Brash, S. (2009) Scheduled napping as a countermeasure to sleepiness in air traffic controllers. Journal of Sleep Research, 18, 11-19.
- Signal, T. L., van den Berg, M. J., Mulrine, H. M. and Garder, P. H. (2012) Duration of sleep inertia after napping during simulated night work and in extended operations. Chronobiology International, 29(6), 769-779.
- Takahashi, M. (2012) Prioritizing sleep for healthy work schedules. Journal of Physiological Anthropology, 31(6).
In the News
Provided below are a selection of articles from around the web on the issues associated with fatigue. We hope you find them useful and interesting.
Dave Philipps, The New York Times, October 2020
Because fatigue can corrode mission performance, a new physical training manual tells soldiers to grab 40 winks when they can, part of a new holistic approach to health in the ranks.
University of South Australia, Science Daily, August 2020
A simple coffee and a quick catnap could be the cure for staying alert on the nightshift as new research shows that this unlikely combination can improve attention and reduce sleep inertia.
SciShow, YouTube, June 2018
A short video explaining the benefits of coffee naps, and why they work so well. With their powers combined, coffee and naps create a greater sum than their parts.
Denis Campbell, The Guardian, February 2020
Help is arriving for overworked NHS staff as a growing number of hospitals bring in sleep pods for doctors and nurses to grab power naps during their shifts.
Tired health care workers can recharge in private, comfortable space after pilot program brings sleeping pods to University Hospitals
Julie Washington, Cleveland.com, October 2020
UH is the first hospital system in the country to install HOHM sleeping pods in a pilot program that put three pods on UH’s main campus in September 2020.