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Sleep Science: Workplace Fatigue Risk Goes Beyond Poor Sleep


What does it mean to be fatigued? For many of us, the answer seems easy – fatigue is sleepiness, plain and simple. That’s why the majority of fatigue interventions and tools center on promoting healthy sleep cycles and sleeping habits.


But fatigue goes beyond a night of poor sleep. Scientific research indicates that sleeplessness isn’t the only culprit. Other factors including emotional exhaustion, irregular shift work, tedious tasks, and physical exertion can lead to more acute and chronic fatigue. In order to effectively combat fatigue in the workplace, companies need to target a much wider variety of sources. In this article, we will review the types of fatigue, how fatigue can manifest itself in your workforce, and strategies for addressing fatigue.


Understanding Types of Fatigue

Leading fatigue research suggests that although sleepiness can certainly be a symptom of fatigue, it is critical that fatigue assessments approach fatigue as a complex issue with different potential presentations. In a 2006 study by Shen et al., the researchers argued that fatigue is best understood in two broad categories: physiological and psychological. The differences are as follows:


  1. Physiological fatigue results in decreased muscular or organ capacity, which can look like reduced strength, energy, or the classic tiredness.

  2. Psychological fatigue, on the other hand, results in decreased motivation, emotional exhaustion, and increased stress. This type of fatigue can result in forgetfulness, slowed reaction times, increased errors, or burnout.


Critically, while psychological and cognitive fatigue can be caused by sleep interruptions, they do not require them. Strained relationships with family and friends, for instance, can lead to emotional exhaustion and psychological fatigue. Furthermore, such personal conflicts can themselves impact levels of stress and quality of sleep, which will only worsen fatigue across all categories.


When recognizing fatigue, it is also important to consider duration. Acute fatigue is temporary and episodic, has a rapid onset, and can be alleviated via rest, exercise, or stress management. Prolonged fatigue generally lasts at least a month and is persistent. Chronic fatigue is defined by six consecutive months and is persistent, has a slow onset, and cannot be easily alleviated via normal relief channels.


Fatigue in the Workplace

Fatigue is an important safety issue that is now being recognized by industry leaders and employers. The National Safety Council estimates that a typical employer with 1,000 workers is likely to face an annual loss of over $1 million attributed to fatigue.


Unfortunately, there are many realities of in certain industries like mining, long haul trucking, and construction work that reliably contribute to fatigue. Jobs in these industries call for difficult physical work, require long hours, and often consist of repetitive tasks. While each of these factors alone could cause fatigue, the combination of the three almost guarantees it.


Another hurdle some industrial occupations that run on a 24-hour schedule is the lack of natural light for some shift workers. Our bodies’ circadian rhythms are deeply reliant on a consistent cycle of sunlight and darkness. Any worker who consistently works a night shift will experience a guaranteed disruption of their circadian rhythms. The underground nature of mining makes miners uniquely vulnerable to circadian disruption whether on the day or night shift.


How to address fatigue in the workplace

Researchers on fatigue advise that managing requires standardizing shifts as much as possible. By giving workers a consistent and predictable schedule, employers can minimize disruptions and allow their workers to adjust to a reliable sleep schedule. This approach is made more effective when paired with efforts to increase natural light exposure so they can further reinforce a healthy circadian rhythm.


Second, employers can focus their interventions on “pressure points”, or times when fatigue is most likely to peak. According to a study by Talebi et al. (2021), fatigue tends to increase steadily over the course of a typical night shift, while day shift fatigue tends to peak around 1 p.m. The researchers also found higher rates of fatigue during summer and winter. Safety managers can supplement their fatigue detection protocols with additional testing and intervention at these pressure points.


Finally, given that fatigue is a deeply multifaceted phenomenon, it is in the best interest of employers to rely on fatigue assessment tools to monitor workers. In addition to wearable devices, cognitive assessment apps like DRUID from Impairment Science can effectively detect fatigue-related impairment regardless of cause. By implementing DRUID in your workplace, you can attack fatigue in an objective way without singling out lack of sleep. For further learning, the National Safety Council has an extensive fatigue information section on their website including a fatigue cost calculator.


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