What is mental work / fatigue / toughness / health?

It’s confusing. There is a growing awareness of the importance of mental health in the workplace. That’s good. On the other hand, work can be demanding mentally, but is this bad? In this article we explain what mental workload is and suggest avoidance of terms such as mental fatigue and mental toughness as they are, at best, ambiguous and, often, misleading. We also show how mental workload links to mental health.

Mental workload

We should not lose sight of the fact that working involves mental workload. Mental workload is the amount of cognitive processing utilised in order to meet the requirements of the task. It is the cognitive cost of achieving the outcome sought from any given task. Writing a presentation involves mental workload, as does analysing spreadsheet data, as does problem solving with colleagues. But just because it involves mental workload doesn’t make it a mental health issue.

The mental workload required in a task may be affected by past experience and or the support available. The mental workload experienced can vary from individual to individual. For example, someone experienced at using a spreadsheet may find a task involving the analysis of quantitative data much less mentally demanding than someone inexperienced in the use of spreadsheets. Thus, with appropriate training, the mental workload demands of a task can be reduced, freeing up capacity to work on other things. Upskilling someone can mean you free up their cognitive resources so they have the bandwidth to cope with more tasks.

Central to the concept of mental workload is the notion of limited mental resources; once the demands of a task exceed available mental resources, performance decreases and task failure is more likely to occur. Sufficient overload in the demands of a task can become a mental health issue.

Mental fatigue

More problematic is the term mental fatigue. Just after the first world war, in an analysis of fatigue for the UK Industrial Research Board, an advisory body under the Medical Research Council concluded that the term fatigue had no place in scientific discussion because it was impossible to determine precisely what it is. Over 80 years later scientists concluded that the definition of fatigue remains problematic. Fatigue does not have a linear relationship with time or level of exertion in that the longer the period of work, or the greater the demand of work, the higher the level of mental fatigue. This is because the level of motivation impacts on the level of fatigue. High levels of workload lead to mental fatigue when the rewards associated with that effort are low, and high levels of workload can be sustained without experiencing mental fatigue when the rewards are perceived to be high. Thus a manager might struggle to complete a complex report late on a Friday because they see the report as an unnecessary distraction, whereas another manager might be highly motivated to complete the report because they see completing the report as a critical element in securing promotion. The mental workload involved in completing the task may be the same for both people. To put it more simply, you may not be bothered to do a task if the reward is £10, but make it £1m and you’d be up and at it. Motivation can trump fatigue. As a guiding principle, when something is seen as fatiguing, figure out the contributory elements that are perceived to result in fatigue. These are things you may be able to manage, but fatigue itself is too vague and ambiguous a concept to be useful.

Mental toughness

Mental toughness is a similarly problematic term to mental fatigue. In contrast to mental fatigue, which represents declining motivation, mental toughness refers to the maintenance of effort as a function of an individual's values, attitudes, emotions and cognition, in spite of pressure or adversity. Mental toughness is considered a personality trait. But there is still much debate as to what mental toughness actually is.

Despite the ambiguity of what mental toughness is, there is a consensus of opinion that suggests mental toughness is developed over long periods of time. But do we really want a workforce of mentally tough people? For example, do we want medics who are mentally tough? Or would we prefer them to have greater sympathy and empathy with those for whom they care? The value of mental toughness depends on the context. It may be a very useful attribute for a mountaineer looking to scale Everest but profoundly unhelpful for someone who looks after the more vulnerable members of society.

Mental health

Maintaining the mental health of the workforce is a good thing. The World Health Organisation defines mental health as a “state of mental well-being that enables people to cope with the stresses of life, realise their abilities, learn well and work well, and contribute to their community. It is an integral component of health and well-being that underpins our individual and collective abilities to make decisions, build relationships and shape the world we live in.”

By providing the right training and motivation we can help people optimise their mental resources for the benefit of themselves and the organisation. Success in the long term means developing the skills and having the tools to make the most of the cognitive resources we have and recognising the fact that work at times results in significant mental workload.

Dr Dominic Irvine and Professor Emeritus Simon Jobson