Why more coffee isn’t the answer to work fatigue
Work fatigue isn’t really treated with the level of attention it deserves. How often do we allude to it being something to push through until the weekend or manage with an extra coffee? In reality, it is a serious safety risk that affects how people think, react and make decisions at work. When fatigue is combined with substance use, that risk increases significantly. For employers and safety leaders, understanding this connection is essential to preventing incidents and supporting worker wellbeing.
Work fatigue is more than feeling tired at the end of a shift. It is a state of physical or mental exhaustion that reduces a person’s ability to perform work safely and effectively. It can be caused by long hours, inadequate sleep, high workload, stress or mental illness, or irregular schedules such as shift work. Fatigue often builds over time, which means workers may not recognise how impaired they have become until performance is already affected.
Work fatigue means poor functioning
Fatigue is one of the most commonly cited risk factors in workplace injuries, with shiftworkers have more than double the injury rate of non-shiftworkers.
Fatigue has a direct impact on cognitive and physical functioning. It slows reaction times, reduces attention and impairs judgement. Workers experiencing fatigue are more likely to make errors, overlook hazards or take shortcuts. Research has shown that fatigue can affect performance in ways similar to alcohol impairment, particularly in tasks that require sustained attention or quick decision making. Being awake for 17 hours can impair performance equivalent to a 0.05 blood alcohol level.
It’s not just fatigue that’s the issue; it’s burnout as well. More than 61% of Australian workers have reported experiencing burnout.
Are fatigue and substance use connected?
The link between fatigue and substance use isn’t always straightforward but it often feeds into a bit of a cycle. Fatigue can lead workers to use substances as a way to cope with demanding or tiring conditions. Stimulants (such as methamphetamines etc) may be used to stay alert during long shifts, while alcohol or other depressants may be used to relax or fall asleep after work.
“Workers who have difficulty sleeping sometimes use alcohol and/or drugs to help,” according to the Your WorkLife publication by Flinders University.
At the same time, substance use can worsen fatigue. Alcohol disrupts sleep quality, even if it initially helps with falling asleep. Other substances can interfere with the body’s natural recovery processes, leading to ongoing tiredness and reduced performance. Over time, this creates a cycle where fatigue and substance use feed into each other.
There is also a strong connection between fatigue, mental health, and substance use. Evidence shows that mental health challenges and substance use frequently co-occur, with fatigue acting as both a symptom and a contributing factor. When workers are physically and mentally depleted, they are more vulnerable to unhealthy coping strategies.
“…unmanaged burnout can put workers at a higher risk of developing mental health problems. It can lead to exhaustion, anxiety, depression, and significant health risks for employees,” reports Mental Health First Aid International.
What industries are affected the most?
Some industries face a higher risk due to the nature of the work. Construction, transport, mining, aviation and healthcare are common examples where long hours, physical demands and irregular schedules are part of the job. In these environments, fatigue is often normalised, which can make it harder to identify when it becomes a safety issue. When substance use is layered on top of this, the potential for harm increases.
In these safety-critical environments, even small lapses can have serious consequences.
Is work fatigue something employers should worry about?
Definitely. Fatigue and substance use are not just individual or employee issues. They have direct implications for workplace safety, productivity and culture. Fatigued workers are more likely to be involved in incidents, require time off, or struggle with consistent performance. When substance use is involved, the risks extend further, affecting team dynamics, morale, and overall safety outcomes. And the law states that you are responsible for providing a safe workplace
Employers have a responsibility to manage these risks as part of their duty of care. “Under the Work Health and Safety Act 2012, as a PCBU, you have the primary duty of care to ensure the health and safety of everyone at your workplace.” Addressing fatigue and substance use together allows organisations to take a more complete and effective approach to safety.
Managing this risk requires a balanced approach that prioritises safety while supporting workers. Clear and well-communicated drug and alcohol policies as well as regular testing is core to your business.
Education also comes into play here. Your workers need to understand how fatigue and substances interact, particularly the impact on sleep, recovery and performance. Providing access to support services, wellbeing programs and early intervention pathways can help address issues before they escalate.
Workplace testing programs can also form part of this approach when implemented thoughtfully and framed as a safety measure rather than a disciplinary tool, so that the whole team knows it’s about accountability and care.