Focus on Fatigue

Issue #73- March 2022

Welcome to Focus on Fatigue!

It’s been a busy few months here at InterDynamics and we are excited to share with you what we’ve been up to.

Our feature article also looks at two recent studies that offer hope for the long term health of shift workers.

We trust you find this issue interesting and informative.

The FRMS Team



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).

InterDynamic News

FAID Quantum Web Service

We are excited to let you know that we have been working hard behind the scenes creating FAID Quantum Web Service. This web based version of FAID Quantum will offer convenience and accessibility along with a modernized user interface. FAID Quantum Web Service will allow us to service an even broader market; expanding our range of options to suit your requirements. FAID Quantum Web Service is still in the early stages of release but is available for trial by visiting and signing up for a free trial account. We welcome your feedback!

Covid Resilient Rostering

We have assisted a number of companies with bespoke Roster Design Solutions, taking into account fatigue and other context specific considerations. Most recently this has included “COVID resilience”; to minimise potential impact of COVID disruption. It is always satisfying looking at a challenging problem and developing workable solutions.

Nimbus Integration

We are pleased to announce that InterDynamics have recently partnered with nimbus to integrate FAID Quantum into nimbus’ time2work system. You can read more about the integration here.

Some good news for shift workers

Diet and exercise do make a difference!

We are constantly hearing about the health implications of shift work and poor sleep, and it is rarely good news. We know that shift workers are at increased risk of health problems, such as digestive upsets, obesity, cardiovascular disease, diabetes, depression and certain cancers, to name a few. However, two recent studies offer some hope.

A study published by the British Journal of Sports Medicine found that exercising according to World Health guidelines could help counteract adverse health outcomes associated with poor sleep. The study particularly looked at cardiovascular disease and cancer mortality. Both poor sleep and physical inactivity have previously been associated with health risks. The study found that while poor sleep is still associated with these negative health outcomes, engaging in moderate to high levels of physical activity appeared to minimise the risk.

Meal Timing
Another study, supported by the National Institutes of Health, looked at the impact of meal timing in night shift work. Eating at nighttime was found to boost glucose levels, while restricting meals to the daytime prevented the high blood sugar linked to night shift work. The effects on glucose are believed to be due to circadian misalignment. Restricting meals to the daytime, may therefore reduce health risks linked to night shift work, particularly diabetes.

Future Interventions
Although there is no substitute for sleep, and more research is needed, studies such as these do offer hope for shift workers. They could lead to practical interventions and assist shift workers to proactively influence their health outcomes.


  • Chellappa S, Qian J, Vujovic N, et al. (2021) Daytime eating prevents internal circadian misalignment and glucose intolerance in night work. Science Advances 7(49).
  • Huang B, Duncan MJ, Cistulli PA, et al. (2021) Sleep and physical activity in relation to all-cause, cardiovascular disease and cancer mortality risk. British Journal of Sports Medicine.
  • Hulsegge, G., Proper, K.I., Loef, B. et al. (2021) The mediating role of lifestyle in the relationship between shift work, obesity and diabetes. Int Arch Occup Environ Health 941287–1295.
  • Monnaatsie M, Biddle S, Khan S & Kolbe-Alexander T. (2021) Physical activity and sedentary behaviour in shift and non-shift workers: A systematic review and meta-analysis. Preventive Medicine Reports24.

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.

High physical activity levels may counter serious health harms of poor sleep

BMJ, Science Daily, June 2021
Physical activity levels at or above the weekly recommended amounts may counter the serious health harms associated with poor sleep quality, suggests a large long term study.

Moving more a shift in the right direction for shift workers

University of Southern Queensland, November 2021
A study by University of Southern Queensland researchers has highlighted the need to improve physical activity among shift workers.

Daytime meals may reduce health risks linked to night shift work

NIH, Science Daily, December 2021
A small clinical trial has found that eating during the nighttime — like many shift workers do — can increase glucose levels, while eating only during the daytime might prevent the higher glucose levels now linked with a nocturnal work life.

Blessed are the shift workers: but how well-rested are they?

Georgia Stynes, ABC, February 2022
In this audio discussion, Siobhan Banks, Director of the Behaviour-Brain-Body Research Centre at the University of South Australia, joined Georgia Stynes to talk about the relationship between sleep and shift workers. They also touch on the role of diet and exercise.

Issue #72- November 2021

Welcome to Focus on Fatigue!

It’s that time of year again! Some of us are springing forward, some of us are falling back and some are staying where they are!  And it’s all thanks to daylight saving!

Some people love it. Some people hate it. But we are all affected by it in some way, even if we don’t live in a place that observes daylight saving time.

In this month’s Focus on Fatigue, we will look at the ‘why?’ and the impact of all this strange time changing.

The FRMS Team



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).

Daylight saving

Why do we do it? And what’s the impact?

Daylight saving time changesWhat’s the point?

The main purpose of daylight saving time, (did you know it is daylight saving not daylight savings?) is to make better use of daylight. We change our clocks during the summer months to move an hour of daylight from the morning to the evening. This allows people to take advantage of light and warmth and participate in evening activity. However, originally the motivation for daylight saving was to save on the use and cost of artificial light.

History of daylight saving

Some people credit Ben Franklin with the invention of daylight saving, which is a bit of a stretch. However, he did write a satirical piece for the Journal de Paris in 1784, suggesting Parisians change their sleep schedules to save money on candles and lamp oil.

Daylight saving was first proposed in earnest by George Hudson in New Zealand in 1895. However, residents of Port Arthur, Ontario (now Thunder Bay) were the first to adopt a period of daylight saving time in 1908, followed by some other locations in Canada. Germany was then the first country to implement daylight saving, in 1916 during World War I, to minimize the use of artificial light to save fuel for the war effort. UK, France and other countries followed suit shortly after, with Australia and Newfoundland adopting daylight saving in 1917 and the U.S. in 1918. Many reverted back to standard time after the war. Since then, it has been adopted on and off in various places for different periods.

Current situation

Approximately 70 countries currently utilise daylight saving time (DST), or summer time, in at least part of the country. Countries near the equator are less likely to observe daylight saving. They have less need for it due to the warmer climate and more consistent daylight hours throughout the year. Even within countries that do observe daylight saving, it is often not adopted by all states and territories.

While the savings on energy may have originally been a valid justification, this advantage no longer stacks up. Our energy use has changed (more energy-efficient lighting, more electrical gadgets and energy sucking air conditioners), negating, or reversing, the energy saving benefit in some instances.

Divided opinions

Daylight saving remains an issue of contention in many places. It continues to be a topic of debate in Europe and America, with future changes likely. Some are pushing to abolish daylight saving time, while others are pushing to adopt daylight saving time all year round.


Daylight saving is problematic for farmers, who have lobbied against it from the beginning. It disrupts their schedules, particularly dairy farmers, and leaves less morning sunlight to get crops to market.

When it comes to conducting global business, constantly changing time zones also present challenges, and not all countries start/end daylight saving at the same time. This means the time difference between two locations can change four times in a year and the situation becomes further complicated when scheduling across multiple locations.

A number of studies have shown negative impacts relating to daylight saving. Most of these relate to the period immediately after the time change, resulting from disruption to circadian rhythm and sleep. Research suggests that the shift to daylight saving raises the instance of heart attack and other cardiac events. A study out of the US found a jump in fatal car crashes in the days following the shift to DST. And another study identified an increase in workplace injuries immediately following the switch to DST.

So, what’s the upside?

Along with those who enjoy the longer summer evenings, there are other benefits too. The extended evening light may result in an increase in physical activity in children and a decrease in robberies. Studies also found that it may result in fewer wildlife killed by vehicles and less road incidents.

Tips to adjust

For those who do have to go through the transition to and from daylight saving time, keep in mind these tips:

  • Start to slowly adjust your body clock in the few days leading up to the start of daylight saving by waking up a little earlier each day.
  • Eat a healthy breakfast first thing in the morning.
  • Spend time outdoors. Go for a walk in natural light.
  • With children, adjust slowly by putting children to bed a little earlier each day in the few days before the change, and reverse the process at the end of daylight saving.


  • Barnes, C. & Wagner, D. (2009) Changing to daylight saving time cuts into sleep and increases workplace injuries. Journal of Applied Psychology, 94(5), 1305–1317.
  • Buckle, A. (n.d.) History of Daylight Saving Time (DST). Time and Date. (Accessed 20/10/2021)
  • Chudow, J. Dreyfus, I. et al (2020) Changes in atrial fibrillation admissions following daylight saving time transitions, Sleep Medicine, 69, 155-158.
  • Doleac, J. & Sanders, N. (2015) Under the Cover of Darkness: How Ambient Light Influences Criminal Activity. The Review of Economics and Statistics 97(5), 1093–1103.
  • Ellis, A. et al. (2016) Daylight saving time can decrease the frequency of wildlife-vehicle collisions. Biology Letters, 12.
  • Ferguson, S., Preusser, D., Lund, A., Zador, P. & Ulmer, R. Daylight saving time and motor vehicle crashes: the reduction in pedestrian and vehicle occupant fatalities
  • Fritz, J., VoPham, T., Wright, K. & Vetter, C. (2020) A Chronobiological Evaluation of the Acute Effects of Daylight Saving Time on Traffic Accident Risk. Current Biology 30(4), 729-735.
  • Goodman, A., Page, A. & Cooper, A. (2014) Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries, International Journal of Behavioral Nutrition and Physical Activity, 11(1), 84.
  • Guven, C., Yuan, H., Zhang, Q., & Aksakalli, V. (2021) When does daylight saving time save electricity? Weather and air-conditioning. Energy Economics98.
  • Jiddou, M. R., Pica, M., Boura, J., Qu, L., & Franklin, B. A. (2013) Incidence of myocardial infarction with shifts to and from daylight savings time. The American journal of cardiology111(5), 631–635.
  • Kantermann, T., Juda, M., Merrow, M. & Roenneberg, T. (2007) The Human Circadian Clock’s Seasonal Adjustment is Disrupted by Daylight Saving Time. Current Biology, 17(22), 1996-2000.
  • Kotchen, M. & Grant, L. (2008) Does Daylight Saving Time Save Energy? Evidence from a Natural Experiment in Indiana. NBER.
  • Küfeoğlu, S., Üçler, S., Eskicioğlu, F., Öztürk, B. & Chen, H. (2021) Daylight Saving Time policy and energy consumption, Energy Reports, 7, 5013-5025.
  • Pacheco, D. (2020) Daylight Saving Time. Sleep Foundation. (Accessed 20/10/2021)

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.

Related Articles

Daylight Saving Time Explained

CGP Grey, You Tube, October 2011
Every year some countries move their clocks forward in the spring, only to move them back in the autumn. To the vast majority of the world who doesn’t participate in this odd clock fiddling, it seems a baffling thing to do. So what’s the reason behind it?

Should we abolish daylight saving time – or apply it across Australia?

Nick Evershed, The Guardian, October 2021
These interactive graphics use sun position calculations to show how daylight saving affects daylight hours, and the effect of any changes

Study analyzes the potential consequences of canceling daylight saving time

Emily Henderson, News Medical, October 2021
A study by José María Martín-Olalla of the University of Seville has analyzed retrospectively and from a physiological perspective the potential consequences of canceling daylight saving time, the biannual change of clocks. In his conclusions, he argues that maintaining the same time during all twelve months could lead to an increase in human activity during the early morning in the winter months, with the potential repercussions on human health that this would entail.

Recent Studies Relating to Sleep and Fatigue

Meeting sleep recommendations could lead to smarter snacking

Ohio State University, Science Daily, September 2021
Missing out on the recommended seven or more hours of sleep per night could lead to more opportunities to make poorer snacking choices than those made by people who meet shut-eye guidelines, a new study suggests.

NASA Lab Studies Sleepiness and Use of Automated Systems

Abby Tabor, NASA’s Ames Research Center, September 2021
Drowsy driving accounts for a large proportion of car crashes, according to the National Highway Traffic Safety Administration. So, you might think self-driving cars would fix that. After all, computers just don’t get sleepy. But today’s vehicles are only partially automated, requiring the human driver to stay alert, monitor the road, and take over at a moment’s notice. A new study conducted by the Fatigue Countermeasures Lab at NASA’s Ames Research Center in California’s Silicon Valley suggests this passive role can leave drivers more susceptible to sleepiness – especially when they’re sleep deprived.

Issue #71 – September 2021

Welcome to Focus on Fatigue!

The benefit of fatigue education and training has come up in conversation with clients a couple of times recently. So, in this month’s Focus on Fatigue, we thought we would delve into the research to determine whether fatigue education is an effective fatigue management strategy.

Our ‘In the News’ section also features a recently released paper on “Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety and health” by the Academy of Sleep Medicine and the Sleep Research Society. This paper is a comprehensive review of fatigue risk management and a valuable resource, which we highly recommend reading.

The FRMS Team



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).

Effective Fatigue Management Training

Is fatigue education and training effective in improving sleep, fatigue and safety outcomes?

An effective fatigue management system

An effective fatigue management system involves multiple layers of protection. One of these layers of protection is promoting and fostering a safety culture that recognises fatigue as a safety concern. Organisations and individuals that recognise fatigue as a safety concern are more likely to respond appropriately as fatigue-related risks escalate. A culture of concern can be stimulated by adequate fatigue education and training that focuses on managing fatigue-related risks for the organisation as well as the individual.

Studies on fatigue education & training

A number of studies have looked at the effectiveness of fatigue education and training in the workplace. These studies have been conducted in various industries including emergency medical services, health care, policing, trucking and aviation. The interventions varied in delivery method, length and content but included fatigue training and/or sleep health education.

Benefits of fatigue education and training

Some of the benefits observed following fatigue education and training programs were:

  • Improvements to patient safety and personal safety
  • Improvement in sleep quality
  • Reduction in ratings of acute fatigue, stress and burnout
  • Individuals more likely to identify and seek treatment for sleep disorders
  • Improvement in fatigue management knowledge, self-efficacy, attitude & behavioural intention

Factors influencing effectiveness of training

Certain factors were found to improve the effectiveness of training in some of the studies:

  • Training was found to be more effective when it included content specific to the work setting and tasks
  • Training delivered via lecture style or expert led training was more effective than other methods
  • Adoption of trained behaviour was more likely when supported by a company safety culture
  • Revisiting training every two years assisted retention of benefits

Fatigue education programs equip the individual with the tools and knowledge to proactively manage the effects of atypical work schedules. This assists in putting fatigue risk on the radar and reducing fatigue related incidence.


  • Arora, V. M., Georgitis, E., Woodruff, J. N., Humphrey, H. J., & Meltzer, D. (2007). Improving sleep hygiene of medical interns: can the sleep, alertness, and fatigue education in residency program help?. Archives of internal medicine167(16), 1738–1744.
  • Barger, L. K., Runyon, M. S., Renn, M. L., Moore, C. G., Weiss, P. M., Condle, J. P., Flickinger, K. L., Divecha, A. A., Coopler, P. J., Sequeira, D. J., Lang, E. S., Higgins, J. S. & Patterson, P. D. (2018) Effect of Fatigue Training on Safety, Fatigue, and Sleep in Emergency Medical Services Personnel and Other Shift Workers: A Systematic Review and Meta-Analysis, Prehospital Emergency Care22:sup1, 58-68.
  • Barger, L. K., O’Brien, C. S., Rajaratnam, S. M., Qadri, S., Sullivan, J. P., Wang, W., Czeisler, C. A., & Lockley, S. W. (2016) Implementing a Sleep Health Education and Sleep Disorders Screening Program in Fire Departments: A Comparison of Methodology. Journal of occupational and environmental medicine58(6), 601–609.
  • Fournier, PS., Montreuil, S. and Brun, JP. (2007) Fatigue Management by Truck Drivers in Real Life Situations: Some Suggestions to Improve Training. Work  29(3), 213 – 224.
  • Gander, P, Marshall, N, Bolger W & Girling I (2007) An evaluation of driver training as a fatigue countermeasure, Transportation Research Part F: Traffic Psychology & Behaviour, 8(1), 47-58.
  • Garbarino, S., Tripepi, G. & Magnavita, N. (2020) Sleep Health Promotion in the Workplace. International Journal of Environmental Research and Public Health, 17(21), 7952.
  • Hu, C. J., Lee, F. P., & Hong, R. M. (2020) Fatigue Management Health Education Intervention Effects on Flight Attendants. Aerospace medicine and human performance91(12), 911–917.
  • James, L., Samuels, C. H., & Vincent, F. (2018) Evaluating the Effectiveness of Fatigue Management Training to Improve Police Sleep Health and Wellness: A Pilot Study. Journal of occupational and environmental medicine60(1), 77–82.
  • Machin, M. (2017) A Evaluating a Fatigue Management Training Programme for Coach Drivers in L. Dorn (Ed), Driver Behaviour and Training, (pp. 75-83). Aldershot, UK: Ashgate
  • Smidt, M, Mitchell, D & Logan, K (2021) The Potential for Effective Training of Logging Truck Drivers, Journal of Agricultural and Biological Engineers, 27(1), 29-41.

Columbia River Bar Pilots See Value in Fatigue Training

InterDynamics recently conducted another successful fatigue training workshop with Columbia River Bar Pilots. Columbia River Bar Pilots have shown a strong commitment to fatigue management over many years and enlist InterDynamics to periodically conduct managing fatigue training workshops as part of this commitment.

Derek from Columbia River Bar Pilots offered the following reflection:
The Columbia River Bar Pilots employ a robust fatigue management system that benefits from periodic in-person training on fatigue and sleep science.  Healthy sleep promotes safety by improving alertness and decision-making to prevent accident and injuries to our pilots.”

InterDynamics’ Managing Fatigue Training Workshops have been successfully utilised across aviation, construction, energy, rail and marine industries; equipping participants with general awareness information on managing fatigue, as well as managing the social and lifestyle impacts of working shift work. The workshops provide personally relevant and practical techniques for managing individual fatigue.

Related Research

Effect of Fatigue Training on Safety, Fatigue and Sleep in Emergency Medical Services Personnel and Other Shift Workers: A Systematic Review and Meta-Analysis

Barger, L. K., Runyon, M. S., Renn, M. L., Moore, C. G., Weiss, P. M., Condle, J. P., Flickinger, K. L., Divecha, A. A., Coopler, P. J., Sequeira, D. J., Lang, E. S., Higgins, J. S. & Patterson, P. D. (2018)


Background: Fatigue training may be an effective way to mitigate fatigue-related risk. We aimed to critically review and synthesize existing literature on the impact of fatigue training on fatigue-related outcomes for Emergency Medical Services (EMS) personnel and similar shift worker groups.

Methods: We performed a systematic literature review for studies that tested the impact of fatigue training of EMS personnel or similar shift workers. Outcomes of interest included personnel safety, patient safety, personnel performance, acute fatigue, indicators of sleep duration and quality, indicators of long-term health (e.g., cardiovascular disease), and burnout/stress. A meta-analysis was performed to determine the impact of fatigue training on sleep quality.

Results: Of the 3,817 records initially identified for review, 18 studies were relevant and examined fatigue training in shift workers using an experimental or quasi-experimental design. Fatigue training improved patient safety, personal safety, and ratings of acute fatigue and reduced stress and burnout. A meta-analysis of five studies showed improvement in sleep quality (Fixed Effects SMD −0.87; 95% CI −1.05 to −0.69; p < 0.00001; Random Effects SMD −0.80; 95% CI −1.72, 0.12; p < 0.00001).

Conclusions: Reviewed literature indicated that fatigue training improved safety and health outcomes in shift workers. Further research is required to identify the optimal components of fatigue training programs to maximize the beneficial outcomes.

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.

AASM, Sleep Research Society Issue Guidance on Work Shift Duration for Employers

Matthew Gavidia, AJMC, July 2021
The Academy of Sleep Medicine and the Sleep Research Society issued guiding principles for employers on designing optimal work shift durations in the workplace, which address risk factors, countermeasures, and shared decision-making implications. The complete paper can be accessed here.

Owls and larks do not exist: COVID-19 quarantine sleep habits

AMHSI Research Team, Science Direct, January 2021
The coronavirus pandemic presented a unique opportunity to study the daily temporal patterns and sleep habits of humans. The question to be explored was: Are there discernible differences in sleep between the normal operational environment and the stay-at-home condition?

Issue #70 – July 2021

Welcome to Focus on Fatigue!

Do you rely on coffee, or another form of caffeine, to get you up and going in the morning, to counteract the mid afternoon slump or to get you through the night shift? If so, you are not alone! Caffeine is consumed by over 80% of U.S. adults.

Caffeine is a stimulant, widely known to help you stay awake and stave off tiredness. However, in this month’s Focus on Fatigue, we will look at how effective caffeine is in counteracting the affects of sleep deprivation and whether it has it’s limits.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).

Caffeine can only do so much….

A recent study from MSU’s Sleep and Learning Lab has assessed how effective caffeine is in counteracting the negative effects of sleep deprivation on cognition. The study found that while caffeine counteracted impairment caused by sleep deprivation on a simple attention task (PVT), it did not significantly affect performance in a more challenging placekeeping task (UNRAVEL).

Placekeeping ability is a cognitive control process that plays a role in procedural performance, problem solving and other higher order tasks. It is the ability to perform the steps of a complex task in a prescribed order without skipping or repeating steps.

The study concluded that this finding “has implications for intervention research and suggests that caffeine has limited potential to reduce procedural error rates in occupational settings”.

While there are short term benefits to consuming caffeine during periods of sleep loss, it is worth being aware of caffeine’s limitations. Let’s break down what we know.

Caffeine can:

  • Increase alertness and reduce fatigue
  • Improve mood
  • Help maintain cognitive performance – Caffeine can help counteract degraded cognitive task performance due to sleep deprivation on vigilance tasks and simple tasks that require sustained focus and response.
  • Help maintain physical performance

However, caffeine can also…

  • Make you overconfident – Caffeinated people are more likely to feel confident about their work performance, even when that performance has suffered. This may have serious consequences in real-life situations where accurate self-perception is crucial for avoiding risks.

Caffeine does not:

  • Help with complex decisions – Caffeine does not help you make complex decisions in the face of changing information. While the effects of caffeine consumption on complex decision making have not been well researched, one study did find that a moderate dose of caffeine did nothing to reverse the effects of sleep deprivation in this sort of context. In other words, drinking coffee may make you feel alert, but it may not help you think more clearly in complex situations.
  • Improve performance in complex tasks – Caffeine does not appear to significantly counteract performance impairment, caused by sleep deprivation, in procedural performance, problem solving and other higher order tasks.
  • Replace sleep – Sleep gives your brain time to conduct a whole host of basic maintenance jobs that it simply cannot do when you’re awake.

While caffeine can be a useful tool, it does have it’s limitations and there is no real substitute for sleep!


  • Kamimori, G.H., McLellan, T.M., Tate, C.M. et al. (2015) Caffeine improves reaction time, vigilance and logical reasoning during extended periods with restricted opportunities for sleep. Psychopharmacology 2322031–2042.
  • Ker, K., Edwards, P. J., Felix, L. M., Blackhall, K., and Roberts, I. (2010). Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database of Systematic Reviews, 5, CD008508.
  • Killgore, W. D. S., Lipizzi, E. L., Kamimori, G. H. and Balkin, T. J. (2007) Caffeine effects on risky decision making after 75 hours of sleep deprivation. Aviation, Space and Environmental Medicine, 78, 957-962.
  • McLellan, T., Caldwell, J. & Lieberman, H. (2016), A review of caffeine’s effects on cognitive, physical and occupational performance. Neurosicence & Biobehavioral Reviews, 71, 294-312.
  • Smith, A. (2002) Effects of caffeine on human behaviour. Food and Chemical Toxicology, 40(9), 1243-1255. http://doi.org10.1016/s0278-6915(02)00096-0
  • Smith, P. F., Smith, A., Miners, J., McNeil, J. and Proudfoot, A. (2000) The safety aspects of dietary caffeine. Expert Working Group on Caffeine. Australia New Zealand Food Authority. Canberra, Australia.
  • Stepan, M. E., Altmann, E. M., & Fenn, K. M. (2021). Caffeine selectively mitigates cognitive deficits caused by sleep deprivation. Journal of Experimental Psychology: Learning, Memory, and Cognition. Advance online publication.

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.

Don’t count on caffeine to fight sleep deprivation

Michigan State University, Science Daily, May 2021
Sleep scientists assessed how effective caffeine was in counteracting the negative effects of sleep deprivation on cognition.

How overwork is literally killing us

Christine Ro, BBC, May 2021
Alarming new research shows that people working more than 54 hours a week are at major risk of dying from overwork. It’s killing three-quarters of a million people each year.

How caffeine and alcohol affect your sleep

Matt Walker, Sleeping with Science, July 2020
Caffeine wakes you up, and alcohol makes you nod off, right? It’s not that simple. Sleep scientist Matt Walker takes us into the eye-opening ways that these drinks affect the quantity and quality of our sleep

Issue #69 – May 2021

Welcome to Focus on Fatigue!

Do you suffer from revenge bedtime procrastination? In this month’s Focus on Fatigue, we will look at what it is and how you can beat it.

Sleep well!

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).


Revenge Bedtime Procrastination


A new term has recently emerged and is circling the internet: ‘Revenge Bedtime Procrastination’.

Where did the term come from?

The term seems to have originated out of China by workers who work the 996 schedule (working from nine in the morning to nine in the evening, six days a week). They coined the term ‘bàofùxìng áoyè’, which translates ‘revenge bedtime procrastination’ or ‘retaliatory staying up late’. Use of the term spread rapidly last year after it was shared on twitter; obviously striking a chord with many!

What is it?

Revenge bedtime procrastination describes the phenomenon where people put off going to bed to carve out ‘me-time’ at the end of a busy day. For many, too tired to do anything intentional or productive, this time is spent mindlessly scrolling social media or watching tv.

Why ‘revenge’?

Those who work long hours can feel like they have little control over their time and are left with no leisure time. As a way of getting ‘revenge’, or fighting back, on this lack of control and free time, they stay up late.

What we know about bedtime procrastination

While the term ‘revenge bedtime procrastination’ may be relatively new, in 2014 a study by Dr Kroese was the first study to present bedtime procrastination as a possible cause for insufficient sleep. The study defined bedtime procrastination as “failing to go to bed at the intended time, while no external circumstances prevent a person from doing so”. This research concluded that “bedtime procrastination appears to be a prevalent and relevant issue that is associated with getting insufficient sleep”. Kroese also makes the point that bedtime procrastination is a particular challenge, as it occurs at the end of the day, when people typically have less mental energy or self-control strength.

Further research in 2018 found “that people who attempted to resist more desires (during the day) were more likely to engage in bedtime procrastination, suggesting that people may be less likely to stick to their intended bedtime after a particularly taxing day.”

How to stop self-sabotaging your sleep

Recommendations to combat bedtime procrastination often involve implementing a bedtime routine and practising basic sleep hygiene, such as maintaining a regular bedtime, having a relaxing pre-bedtime routine, avoiding screens before bed and avoiding caffeine in the hours before bed.

However, as revenge bedtime procrastination also has to do with a feeling of lack of control over one’s day, or lack of ‘me time’, finding ways to carve out such control and time in one’s day can also help. Perhaps by going for a walk during a lunch break, or adding some intention into the way time is spent after finishing work. Look at what is important to you, and intentionally make time for this, even if it is 20 minutes.

Employers can also help by recognising the importance of work/life balance and providing greater work flexibility.



  • Kamphorst, B., Nauts, S., De Ridder, D. & Anderson, J. (2018). Too Depleted to Turn In: The Relevance of End-of-the-Day Resource Depletion for Reducing Bedtime Procrastination. Frontiers in Psychology. 9, 252. http://doi:10.3389/fpsyg.2018.00252
  • Kroese, F., De Ridder, D., Evers, C. & Adriaanse, M (2014). Bedtime procrastination: introducing a new area of procrastination. Frontiers in Psychology. 5, 611. http://doi:10.3389/fpsyg.2014.00611
  • Kühnel, J., Syrek, C., & Dreher, A. (2018). Why Don’t You Go to Bed on Time? A Daily Diary Study on the Relationships between Chronotype, Self-Control Resources and the Phenomenon of Bedtime Procrastination. Frontiers in Psychology, 9, 77.
  • Suni, E., (2021). What is ‘Revenge Bedtime Procrastination’?, Sleep Foundation,


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.

Moonlight may affect sleep cycles

Harvard Health Publishing, April 2021
A recent study found that people fell asleep later and slept for less time over all in the three to five days leading up to a full moon.

Sleeping too little in middle age may increase dementia risk, study finds

Pam Belluck, NY Times, April 2021
The research, tracking thousands of people from age 50 on, suggests those who sleep six hours or less a night are more likely to develop dementia in their late 70s.

New study sheds light on how boredom affects bedtime procrastination and sleep quality

Eric Dolan, PsyPost, April 2021
New research suggests that the inability to be mindfully attentive to the present plays a role in compromised sleep quality. The study also indicates that boredom is an important predictor of bedtime procrastination.

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
320 Adelaide Street Brisbane Qld 4000
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.

Strategic Napping

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 InertiaThis 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.
  • 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 nursing116(5), 26–33.
  • Hilditch, C. J., & McHill, A. W. (2019). Sleep inertia: current insights. Nature and science of sleep11, 155–165.
  • 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 medicine63(10), 843–850.
  • 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 journal24(1), 12–17.
  • 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.

The Army Rolls Out a New Weapon: Strategic Napping

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.

A coffee and catnap keep you sharp on the nightshift, study suggests

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.

Why Do Coffee Naps Recharge You So Well?

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.

NHS hospitals bring in sleep pods to help tired staff take a break

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,, 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.

Issue #67 – January 2021

Welcome to Focus on Fatigue for 2021! We hope you have had a restful holiday period.

We thought we would kick of this year’s Focus on Fatigue by addressing a common question that we receive; “What is an appropriate fatigue tolerance level?” Unfortunately, it is not one that can be answered in a simple sentence. There are a number of factors that need to be considered when setting fatigue tolerance levels, which we will explore in this month’s feature article.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).


What is an appropriate fatigue tolerance level?

Fatigue is inevitable

There are many situations where fatigue is unavoidable; particularly when working across a 24 hour roster, which works against our natural circadian rhythm. This is why we talk about managing fatigue rather than eliminating fatigue. Managing fatigue requires a risk based approach involving a combination of interventions, including managing fatigue exposure, identifying risk, appropriate controls and appropriate fatigue training.

Fatigue tolerance levels

As users of FAID Quantum would be aware, FAID Quantum uses fatigue tolerance levels to assist in its reporting of hours of work related fatigue exposure. FAID Quantum allows the user to set a FAID Score and KSS tolerance level (or multiple tolerance levels). Desired compliance percentages can also be set. FAID Quantum provides reports specific to these settings. So, what is an appropriate fatigue tolerance level?

Task risk and other considerations

When using FAID Quantum, there is no standard fatigue tolerance level recommended. This is because there are a number of considerations when setting a tolerance level.

Not all tasks carry the same risks

Some tasks or roles are more sensitive to fatigue related impairment and/or have significant consequence in the event of a fatigue related error. For example, if someone working an admin role had a micro sleep at their desk, the potential consequences differ to that of a pilot having a micro sleep during final approach. Therefore, the level of fatigue exposure deemed acceptable in different roles may differ.

Controls/protections may be in place

Controls/protections may be in place to reduce the risks associated with fatigue for a particular task/role, impacting the fatigue exposure tolerated.

Fatigue scores are based on the average situation

Hours of work fatigue scores (KSS & FAID Score) are based on average exposure and opportunity for recovery sleep. Some environments may provide the opportunity for more (or less) rest and recovery sleep, influencing the tolerance level that is deemed appropriate. For example, workers living on site, with meals provided and other domestic tasks taken care of, have less commute time and less external time pressures than the average situation.

Workplace culture has a significant impact on the way fatigue issues will be handled by employees within an organisation. Organisational culture is often defined as “the way we do things around here” and is formed by a combination of beliefs, values and assumptions; all of which influence how people interact and behave.

Fatigue Hazard Analysis

To determine an appropriate tolerance level, we recommend an organisation carry out a Fatigue Hazard Analysis (FHA) risk assessment specific to their workplace and tasks. That is, a risk assessment which reviews the hazards of a role when fatigue is present.

Current hours of work fatigue exposure

The FHA risk assessment would consider, amongst other things, the current hours of work fatigue exposure which can be analysed using FAID Quantum. The apparent fatigue tolerance level reports (for KSS & FAID Score) provide an indication of the current hours of work fatigue exposure, most appropriately reflected when at least 6 to 12 months of the most recent actual hours of work data is analysed. It is often helpful for an organisation to take into consideration its current apparent tolerance level in setting a fatigue tolerance level. Until an organisation conducts a FHA, one option is to use the Apparent FAID Score Tolerance Level (FTL) & Apparent KSS Tolerance Level (KTL) as a rough guide. However, it is important to note, the apparent tolerance level does not necessarily represent a safe work environment.

The above apparent fatigue tolerance level reports from FAID Quantum show the current hours of work fatigue exposure of an organisation being at an Apparent FTL of 72 and Apparent KTL of 7.3.

Analysis of fatigue related data

For organisations that have collected fatigue related performance data, FAID Quantum provides the ability to investigate relationships between fatigue exposure (KSS & FAID Score) and the performance data, using the external results function. This may relate to safety incidents, but can also relate to other factors such as absenteeism, complaints or driver efficiency. You can read more here.

This data can provide insight to identify potential correlation between fatigue exposure and incidents. Such analyses can be helpful in determining appropriate fatigue tolerance levels for a particular environment.

Further reading

For further information about setting fatigue tolerance levels and what KSS & FAID Scores represent, you can read Establishing a Fatigue Tolerance Level.

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.

Video: What would happen if you stopped sleeping, day by day

Abby Tang & Andrea Schmitz, Science Insider, November 2020
“Why do we sleep?” has been a notoriously difficult question for scientists to answer, but, “What happens if we don’t?” is actually pretty simple — nothing good. Not getting enough sleep can make you hallucinate, mess with your thinking and memory, and even lead to organ failure. And it doesn’t take very long at all for these negative effects to start occurring. Here’s what would happen to your brain and body, day by day, if you stopped sleeping.

Article: Want your employees to be more productive? Make sure they catch those zzzs.

João Mendes-Roter, Entrepreneur, January 2021
According to the Centers for Disease Control and Prevention, more than one in three American adults fail to get enough sleep on a regular basis — jeopardizing their overall health while making them less productive, more error-prone and at higher risk of injury in the workplace. The annual cost to employers? Research indicates that it’s hundreds of billions of dollars.

Article: Sleep evolved before brains did, study finds

Rachael Rettner, Live Science, January 2021
Our brains need sleep to work properly. But it turns out you don’t need a brain to sleep. In a new study, researchers identified a sleep-like state in a tiny, freshwater animal called a hydra, which has a simple anatomy and lacks a brain.

Issue #66 – November 2020

Welcome to Focus on Fatigue,

We are fast approaching the end of the year, and this is the final edition of Focus on Fatigue for 2020. What a year it has been! Individuals and industries worldwide have seen major change – much of which has been hard, but we have also heard many identify elements of positive change that have occurred alongside the challenges.

As you journey towards the end of 2020, may you also be able to identify positive elements of change that have occurred for you this year.

In this edition of Focus on Fatigue, we are going to look at how workplace culture impacts fatigue management and how cultural change is often needed for effective fatigue management within an organisation.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).


Featured Article

“The way we do things around here”:
How workplace culture impacts fatigue management

Implementing an effective Fatigue Risk Management System (FRMS) is more than just a policy or IT project. It is a cultural change project.

Workplace culture has a significant impact on the way fatigue issues will be handled by employees within an organisation. Organisational culture is often defined as “the way we do things around here” and is formed by a combination of beliefs, values and assumptions; all of which influence how people interact and behave.

When theory and practice don’t align

Organisational culture is sometimes the elusive element to successful fatigue risk management. In many cases, explicit elements of organisational culture (such as policy and procedures) are at odds with implicit elements of organisational culture. Let’s look at a few examples.

A sense of camaraderie and genuine desire not to let colleagues down

In one study of metropolitan train drivers, “drivers expressed concern that leaving mid-shift would be letting their colleagues down and calling into question their ability to operate trains in the future. At the same time, drivers understood that this sentiment was also at odds with the directive of FRMS that required drivers to call in to be relieved when they were too fatigued to continue driving.”¹

This “research identified that drivers would often compromise their own rest opportunities and right to ask for relief because of a strong sense of camaraderie with their peers. Therefore, the cultural particularities of the workplace impacted upon the extent that FRMS could be fully adopted.”¹

Similarly, in another study of hospital nurses, a sense responsibility to their patients and obligation to their unit or team was identified as a barrier to their fatigue management.²

This culture of ‘having each other’s backs’ can simultaneously support and impede fatigue management.

A culture that encourages invulnerability

In some industries, such as healthcare and emergency services, there can be an unwritten expectation to ‘power through’ and portray an image of strength. In some cases, enduring fatigue can even be seen as a badge of honour.

The above mentioned study of hospital nurses, identified a ‘supernurse’ culture as a barrier to effectively managing fatigue and achieving a safety culture. Nurses in the study described “the importance of an appearance of strength. They also commented on a resistance in themselves or amongst their peers in asking for help”. Even when help was being directly offered, it was reported nurses were resistant to accepting it.²

A fear culture around reporting fatigue

A perception of potential negative consequences for reporting fatigue will impede effective fatigue management. In some situations, an employee may feel it will jeopardise future work opportunities or that addressing fatigue is discouraged at a supervisor or management level.

In order to effectively address fatigue, employees need to be able to manage fatigue and provide feedback without fear of repercussion.

A lack of genuine, accessible options

While fatigue management policies may be in place, the associated procedures may miss the mark on being genuinely accessible. For example, if you are expected to take a rest or nap break in your shift, but there is a lack of appropriate space for such a nap or inadequate staff to cover during the break. This is going to promote a culture of pushing through and foster the belief that management are not genuinely invested in fatigue management.

Use of informal strategies

In situations where formal fatigue management strategies may be insufficient or ineffective, informal strategies often emerge to manage fatigue.

One study of volunteer fire-fighters found that fatigue proofing behaviours existed, but they were not openly understood as such. “The study identified informal fatigue management behaviours at the individual, team and brigade level that have evolved in fire-fighting environments and are regularly implemented.” The study provided two recommendations: “(1) to identify and formalise current informal fatigue coping strategies as legitimate elements of the fatigue risk management system; and (2) develop culturally appropriate techniques for systematically communicating fatigue levels to self and others.” ³

Effective FRMS

Genuine concern from the top down

For the issue of managing fatigue risk to be taken seriously within an organisation, it requires a genuine concern to be evident from the top down. Modelled behaviour, systems and structures will all be looked to by staff to determine whether the issue is truly a priority in an organisation. Employees can tell if the issue of fatigue is approached as one of meeting minimum requirements, with little real concern for the issue; or whether the well-being and safety of staff, and ensuing economic benefits of an efficient and effective workforce are truly valued. How the issue is approached and FRMS are implemented will impact and shape company culture around fatigue.

Staff involvement

The above examples highlight the fact that staff engagement and consultation is key to a smooth FRMS implementation, as cultural change at all levels is often required for the organisation to transition its perceptions and management of fatigue in line with the organisation’s fatigue policy commitment.


These examples also highlight the importance of the ongoing review stage of an effective FRMS; to ensure that protection measures implemented are appropriate and effective.


  1. Rainbird, S., Thompson, K. & Dawson, D. (2010). The impact of organisational culture on fatigue management: The case of camaraderie amongst metropolitan train drivers. In: Sargent, C., Darewent, D. & Roach, GD (Eds). Living in a 24/7 world: The impact of circadian disruption on sleep, work and health, Australasian Chronobiology Society, Adelaide, Australia, pp. 29-33
  2. Steege, L. & Rainbow, J. (2017). Fatigue in hospital nurses – ‘Supernurse’ culture is a barrier to addressing problems: A qualitative interview study. International Journal of Nursing Studies, Vol 67, pg 20-28,
  3. Dawson, D., Mayger, K., Thomas, M. & Thompson, K. (2015). Fatigue risk management by volunteer fire-fighters: Use of informal strategies to augment formal policy, Accident Analysis & Prevention, Vol 84, pg 92-98,
  4. Gander, P., Hartley, L., Powell, D., Cabon, P., Hitchcock, E., Mills, A. & Popkin, S. (2011) Fatigue risk management: Organizational factors at the regulatory and industry/company level, Accident Analysis & Prevention, Vol 43 (2), pg 573-590,


InterDynamics News

InterDynamics have continued to successfully deliver FAID Quantum training and FRMS consulting via Internet video conferencing this year. If you have been considering FAID Quantum training or have any other FRMS related queries, we are happy to assist.


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.

Related Articles

Fatigue in air ambulance accident: What we can learn

Integrated Safety Support, August 2020
This week at ISS we’ve been talking about a positive development in the area of fatigue management – and that is a shift in culture towards trust and honesty.

Caledonian Sleeper told by own experts to ‘change culture’ over fatigue as next strike looms

Alastair Dalton, The Scotsman, October 2020
A “change in culture” over staff fatigue is needed at Caledonian Sleeper, according to experts drafted in to investigate the problem which has triggered a series of strikes.

Safety audit says ‘toxic workplace culture’ at Metro rail control center puts riders at risk

Will Vitka, WTOP News, September 2020
“Metrorail has not followed its own fatigue management policies that require at least one day off per week, has not addressed recurring safety issues, and has not implemented adequate recruitment, hiring and training practices,” the report states.

“I’ll Sleep When I’m Dead”: The sleep-deprived masculinity stereotype

University of Chicago Press Journals, Science Daily, September 2020
Men report getting significantly less sleep, on average, than women. A cultural complication is the notion that getting less than the recommended amount of sleep signals something positive about an individual.

Issue #65 – September 2020

Michael J. Fox once said, “Family is not an important thing. It’s everything!”  In this month’s Focus on Fatigue, we will explore the topic of work-family conflict and look at ways employers and employees can reduce the tension for shift workers and their families.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).

Featured Article

Shift Work and Work-Family Conflict

Work-family conflict occurs when the demands of work interfere, or are incompatible, with family life. By nature, shift work, or nonstandard work hours, present challenges to juggling work and family that differ from those experienced with standard work hours.

How can shift work have a negative effect on personal relationships?

Shift work has been found to have modest, but significant, negative effects on familial relationships in some circumstances. These include reduced marital quality and satisfaction, less or reduced quality time with children, increased risk of teenage delinquency, and an increased risk of divorce. A New Zealand study of shift workers who worked long hours in inflexible work schedules found that isolation could also pose a problem in shift worker families, not just for the shift worker but also for the non shift working partner.

Sleep deprivation is a major issue for many shift workers, and the research around this area can also provide insight into the detrimental effects of shift work on families. Studies have found that sleep deprivation is associated with feeling less gratitude towards partners, an increase in interpersonal conflict, reduced empathy and reduced emotional control.

Can shift work have benefits for personal relationships?

The news isn’t all negative, and shift work can indeed provide opportunities that standard hours of employment may not, such as alternative child care arrangements, providing opportunities to spend more time with children during the day, and the ability to attend school functions that might otherwise be problematic. It is certainly the case that some people prefer to work night shifts because those shifts fit in better with the individual’s lifestyle or personal requirements.

Addressing work-family conflict

The issues of work-family conflict relating to shift work are most effectively addressed when seen as a joint concern for both organisations and individuals and approached both through workplace and personal strategies.

What can employers do?

While shift work and nonstandard hours are unavoidable in many industries, research has shown that the following strategies can reduce work-family conflict and increase family time adequacy, as well as increasing job satisfaction and longevity:
– Provide work schedules with advanced notice
– Offer stability in work schedule
– Offer workers greater control over scheduling
– Provide shift work training that includes family involvement and social coping strategies
– Promote a supportive culture that is reflected in policies, practices and supervisor support

What can shift worker families do to strengthen their personal relationships?

What are the most effective strategies shift workers, and their families, can use to ensure that their personal relationships are at an optimum? Unfortunately the research hasn’t yet extended as far as providing evidence-based answers to this very important question. Of course, many shift worker families use a variety of strategies that enable their family to function effectively. For those who would like a few extra hints and tricks, the following strategies have been recommended by researchers in the area:

United we stand

Maintaining a strong family unit in the face of shift work challenges is, partly, about attitude. Every member of the family must be willing to work together and make compromises when necessary. It is impossible for a shift worker to slip into the normal routine of the non-shift working family the moment they walk in the door. It is just as impossible for the non-shift working family members to arrange their lives entirely around the needs of the shift worker. This is not because the different members of the family aren’t trying hard enough, it’s just because they’re out of synch with each other. If everyone works together, perhaps the family can find ways for these two disparate routines to complement each other, instead of clashing head-on.

Recognising mood swings for what they are

As mentioned previously, sleep deprivation lowers people’s emotional stability. We get grumpy, we’re more easily irritated by little things, and we don’t always appreciate our loved ones as much as we would if we were well-rested. If a shift worker comes home from a long night shift and is grumpy, this is not because their personality has changed or because they love their family less, it’s because they need sleep. After they have slept, chances are they’ll revert back to their usual selves. The same is true for anyone who has gone too long without sleep. Recognising these sorts of minor mood swings for the temporary phenomenon they are can help family members understand what’s happening when they occur.

Planning ahead

Many shift work families talk about the importance of The Family Calendar! This is the big planner that hangs on the wall and tells everyone where everyone else is going to be. Shift times will always be the first thing the shift worker adds to the family calendar. This gives other family members an idea of when they may be able to plan time with the shift worker, even if it’s simply having a meal together as a family.

Prioritise sleep

Sleep deprivation is one of the greatest challenges facing shift workers. A lack of sleep will affect every other aspect of a shift worker’s life and, by extension, the whole family. Therefore, it is essential that after shift times are added to the family calendar, sleep times are added next. It is imperative that the family work together to protect these sleep blocks from interruption. The shift worker can ensure they are using good sleep hygiene to increase the chances of getting good quality sleep. Other family members can arrange to either be out of the house at those times, or to keep noise levels to a minimum.
A solid schedule of sleep blocks also provides reassurance for family members regarding the times they can freely make noise without interrupting the sleep of the shift worker. After all, it’s their house too and no one can be quiet all the time.

Making time for each other

After the shift roster and sleep blocks have been added to the family calender. What comes next? Family time, of course. No family can maintain strong relationships without spending time together. This includes time as a family (if children are present) and time as a couple. Quality will generally be more important than quantity. As a couple, it may be necessary to put aside two periods of time where possible. One for talking about household issues such as finances, why the lawn hasn’t been mowed, and the leaky tap in the bathroom. The second for relaxing and enjoying each other’s company.

Making time for me

Everyone needs time away from both work and family in order to maintain their individual sense of self. This may be solitary time for reflection, or it might be time catching up with friends. It may involve participation in a hobby or just reading a good book. Every member of the family in entitled to some time alone, or with friends, both those who are working shifts and those who aren’t.

Communication is key

On a practical level communication can be as simple as making sure everyone knows the roster of the shift worker, and the schedule of everyone else in the household. A shift working parent can’t attend their child’s football game, even if they’re available, if they don’t know it’s on.
On an emotional level, communication is all about checking in with each other. This can include texting during a break or leaving notes for each other. Get creative! For example, draw some simple graph lines on a small whiteboard and hang it in a well-used area of the house. One axis on the graph could indicate energy levels, ranging from ‘exhausted’ to ‘bouncing off the walls.’ The second axis could indicate mood, ranging from ‘everything is awful’ to ‘everything is awesome.’ Each family member has their own magnet to place anywhere on the graph to indicate their present emotional state. For example, Mum might be feeling a little tired (moderate on the energy scale) but she’s happy she accomplished everything she wanted to do today (high on the mood scale). This is a simple concept that can allow each member to tell others in the family how they’re doing, and when they need extra support, without having to say it in words.

When it all goes wrong

Adding shifts to the calendar, adding sleep to the calendar, making time for family, for spouses, for the individual. And don’t forget to find time to wash the dog! Put all this together and it can feel like you need 30 hours in every day just to fit it all in. This, of course, is where compromising comes in. Most people find it impossible to do everything they need to do all the time, whether they are shift workers or not. Therefore, when schedules clash, plans go out the window and the dog is still covered in mud, it will be necessary to be okay with life not working for a while. Throw your hands in the air. Move your magnet to the ‘life is awful’ part of the graph. Laugh. Give each other hugs, even if it’s in the moment before you charge out the door on the way to your next shift. Then try again tomorrow. After all, family is what life is all about!


  • Davis, K. D., Goodman, W. B., Pirretti, A. E. and Almeida, D. M. (2008) Nonstandard work schedules, perceived family well-being, and daily stressors. Journal of Marriage and Family, 70(4), 991-1003.
  • Gee Wilson, M., Polzer‐Debruyne, A., Chen, S. and Fernandes, S. (2007), Shift work interventions for reduced work‐family conflict, Employee Relations, Vol. 29 No. 2, pp. 162-177.
  • Gordon, A. M. and Chen, S. (2013) The role of sleep in interpersonal conflict: Do sleepless nights mean worse fights? Social Psychological and Personality Science, 5(2), 168-175.
  • Handy, J. (2015) Maintaining family life under shiftwork schedules: A case study of a New Zealand Petrochemical Plant. New Zealand Journal of Psychology, 39(1), 29-37.
  • Hendrix, J. A. and Parcell, T. L. (2014) Parental nonstandard work, family processes, and delinquency during adolescence. Journal of Family Issues, 35(10), 1363-1393.
  • Kelly, E. L., Moen, P., Oakes, J. M., Fan, W., Okechukwu, C., Davis, K. D., Hammer, L., Kossek, E., King, R. B., Hanson, G., Mierzwa, F., & Casper, L. (2014). Changing Work and Work-Family Conflict: Evidence from the Work, Family, and Health Network. American sociological review, 79(3), 485–516.
  • Monk, T. H. and Folkard, S. (1992) Making shiftwork tolerable. Taylor & Francis: London, UK.
  • That, Kadri and Mills, Melinda (2016) Out of Time: The Consequences of Non-Standard Employment Schedules for Family Cohesion. Springer Briefs in Sociology: London, UK.
  • Vaghar, M. I., & Masrour, M. J. (2019). A comparative study of satisfaction and family conflicts among married nurses with different working hours. Journal of family medicine and primary care, 8(2), 472–476.
  • White, D. (2018) Shift work and relationships. Psych Central. Retrieved on August 5, 2020, from
  • WorkCover (2020) How to manage shiftwork: Workcover NSW health and safety guide. WorkCover NSW: Gosford, NSW.


In The Research

Shift work interventions for reduced work-family conflict

Marie Gee Wilson, Andrea Polzer-Debruyne, Sopie Chen, Sonia Fernandes (2007)
Employee Relations, Vol.29 No.2, pp.162-177.


Purpose – This research aims to investigate the efficacy of family involvement in shift work training targeting both physiological and social coping strategies.
Design/methodology/approach – The study utilized repeated surveys of work-family conflict (WFC) and family-work conflict (FWC) in a naturally occurring field experiment. Three small process manufacturing sites introduced training for shift workers, with or without family involvement, and with or without training on managing relational aspects of shift-work.
Findings – The inclusion of social coping strategies combined with family involvement significantly reduced work-family conflict. Open response categories on the survey suggest that these reductions were due to the facilitation of a joint problem solving approach by family members. In contrast, employee focused training on physiological coping alone appears to increase family conflicts.
Research limitations/implications – As a field study, this paper cannot control for the particularities of family situations. It should also be noted that the participants were all male, and results may have differed for female shift workers given differing family and work expectations.
Practical implications – For employers and OSH officers, this research suggests that broader spectrum training may assist shift workers in managing the requirements and impact of unsociable hours of work. For the shift worker, the research reinforces the importance of family support and family involvement in moderating shift work’s potentially negative effects.
Originality/value – This is the first study to assess the impact of family involvement in training and development-based interventions. This paper provides a unique perspective on shift work interventions by documenting both content and process effects for shift work support.

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.

Related Articles

Why 9 to 5 isn’t the only shift that can work for busy families

University of Washington, Science Daily, June 2018
For the millions of Americans who work “nonstandard” shifts — evenings, nights or with rotating days off — the schedule can be especially challenging with children at home. But a new study from the University of Washington finds that consistent hours, at whatever time of day, can give families flexibility and in some cases, improve children’s behavior.

Unpredictable work hours and volatile incomes are long term risks for American workers

Katherine Guyot and Richard V. Reeves, Brookings, August 2020
Debates about working time tend to focus on quantity. Are American workers having to put in too many hours, especially those with caring responsibilities? This is of course a vitally important question. But it is not the only one. It matters not only how many hours people work, but how much control they have over them.

Recent Studies Relating to Sleep and Fatigue

Optimistic people sleep better, longer, study finds

University of Illinois at Urbana-Champaign, News Bureau, Science Daily, August 2019
People who are the most optimistic tend to be better sleepers, a study of young and middle-aged adults found.

Bad sleep can cause migraines two days later, new study finds

Abby Moore, Mind Body Green, December 2019
For the one in seven people who suffer from migraines, that inability to fall asleep can have even worse effects, according to new research.

Smelling your lover’s shirt could improve your sleep

University of British Columbia, Science Daily, February 2020
The scent of a romantic partner can improve sleep, suggests new psychology research.

Having trouble sleeping? Try forgiving someone

Sophie McMullen, The Washington Post, October 2019
You may have tried a bedtime meditation or a technique such as the military method to help you fall asleep, but according to a study published last month in the Journal Psychology and Health, there’s another practice you could consider instead: forgiveness.

Issue #64 – July 2020

Welcome to Focus on Fatigue!

While some workplaces have slowed down in recent months, here at InterDynamics we have been working hard on the latest version of FAID Quantum. In this month’s Focus on Fatigue we introduce you to FAID Quantum v1.1 and its new capability. We will also look at some of the potential, measurable impacts that fatigue can have in a workplace.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
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).

InterDynamics News

New Version FAID Quantum

We are pleased to announce that InterDynamics are releasing FAID Quantum v1.1. This new version includes an exciting new feature allowing external results data to be imported and reviewed in conjunction with predicted FAID and/or Karolinkska Sleepiness Scale (KSS) Scores at that time.

This allows the possibility of analysing data and reviewing if fatigue is a factor relating to events such as: accidents, incidents, errors, near misses, excessive braking, complaints, absenteeism or sick leave.

This analysis can play an important step in developing a Fatigue Risk Management System and assist in informing an appropriate fatigue tolerance threshold for different tasks and environments.

The external results feature also allows external measures of fatigue, such as self-reported KSS and PVT results, to be analysed against predicted KSS and FAID Scores to review correlation.

Some of the ways that this capability has already been put to use are featured in the below article.

Featured Article

Impacts of Fatigue in the Workplace


The dangers of fatigue in the workplace in relation to safety are well recognised and shown in many studies. Here is one example where an organisation has used a large data set of incidents and analysed this data against hours of work fatigue scores, using FAID Quantum. An increasing trend of incident rates (incidents per million hours worked) was identified with increases of FAID Scores beyond 40 and KSS Scores beyond 7.While much of the discussion around workplace fatigue focuses on risk of incidents and injury, safety is not the only concern when it comes to workplace fatigue. The other effects of fatigue in the workplace may be more subtle and sometimes go unnoticed or unacknowledged. However, they can still have a considerable impact on an organisation.


One study¹, using FAID Quantum, looked at U.S. police rosters and found a correlation between fatigue and public complaints. The study concluded that “greater predicted fatigue and sleepiness levels, and reduced 24 hr sleep estimates increased the odds of a public complaint against an officer. Consecutive night shifts increased predicted fatigue, reduced 24 hr sleep estimates and increased odds of a public complaint against an office. Off-duty court hours further restricted sleep estimates, further increased predicted fatigue, and further increased the odds of a public complaint.”


Another recent study², using FAID Quantum, looked at U.S. police officers and absenteeism. This study found that greater predicted sleepiness was associated with higher odds of absenteeism the next workday, in particular for afternoon and night shift workers. Absenteeism has a flow on impact on an organisation through staff shortage, management time, lost productivity and decreased morale.

Driver Efficiency

In examining the effects of fatigue on train drivers (loco engineers), one study³ found a significant correlation between predicted fatigue scores and fuel use. Drivers in the moderate fatigue group used 4% more, and drivers in the high fatigue group used 9% more fuel than drivers in the low group. Therefore the cost of fuel significantly increased when using high fatigue drivers. The study further found that high fatigue drivers engaged in more heavy brake and maximum speed violations. These variations in the high fatigue group represent a reduction in planning, efficiency and safety.

Developing a Fatigue Risk Management System

The potential impacts of fatigue in a workplace are far reaching. Identifying and understanding where fatigue may be impacting your business is one step in developing an appropriate Fatigue Risk Management System. You can read more about InterDynamics Risk-Based Approach to Fatigue Management here.


1. Dawson, D., Riedy, S & Vila, B. (2019), US Police Rosters: Fatigue and Public Complaints. Sleep, Volume 42, Issue 3,

2. Riedy, S., Dawson, D., Fekedulegn, D., Andrew, M., Vila, B., and Violanti, J. (2020), Fatigue and Short-term Unplanned Absences Among Police Officers, Policing: an International Journal,

3. Dorrian, J., Hussey, F., & Dawson, D. (2007) Train Driving Efficiency and Safety: Examining the Cost of Fatigue, Journal of Sleep Research, Volume 16, Issue 1,

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.

For Further Consideration

Work-related Fatigue and Job Design
Dr Carmel Harrington and Professor Drew Dawson, Safe Work Australia, 2016
In this seminar, Dr Carmel Harrington and Professor Drew Dawson examine why fatigue management is important from both a worker and a business perspective and what businesses and workers can do to manage the risks caused by fatigue in the workplace.

Fatigue Risk Management in the Workplace
ACOEM Task Force on Fatigue Risk Management, Journal of Occupational and Environmental Medicine, 2012
The purpose of this article is to provide information to assist OEM physicians in these roles. It is designed to provide background, key concepts, and references needed to promote and support an FRMS.

In the News

We’ll be challenging the rail industry – regulator speaks out on fatigued worker death
Ian Weinfass, Construction News, 10 June 2020
Railway contractors should prepare to be challenged over how they manage workers carrying out dangerous tasks while on long shifts.

South African Gold Mine Operations Scheduling

Real time job allocation in underground wet mine.

Bluescope Steel Loco Analysis

Examining plant machinery end of life replacement alternatives for optimum economic viability

Hanson Block Production Planner

Enhancing multi site production operations using historical information and future growth projections

Assigned Services Planning Tool – Workforce Scheduling

Assisting railway engineers/train drivers to have a better work life balance.

Iron Ore Supply Chain Simulation Software

Optimizing complex supply chains to meet short and long term planning goals.