• 06.19.12

Retraining Your Response To Stress And Mental Fatigue

Research into stress reveals that building mental toughness is similar to building physical toughness–here’s how you take advantage of it in the workplace.

Retraining Your Response To Stress And Mental Fatigue

A toughened individual welcomes novelty as a challenge, sees in it an opportunity for gain; an untoughened individual dreads it as a threat and sees in it nothing but potential harm. What is intriguing about research into toughness is the finding that to each of these attitudes–viewing novelty as a challenge or as a threat–there corresponds a distinctive physiological state.


Some scientists, recognizing that mental toughness corresponds to a physiological profile, have gone a step further and asked, can this toughness be trained? Scientists who think the answer is yes have built their research upon a curious finding–that resilience to stress comes from experiencing stress.

Sports scientists know, for instance, that to expand aerobic capacity athletes must endure a training process that shocks their muscles and taxes their cardiovascular systems, to the point of inflicting mild damage to tissues, and then punctuates this process with periods of rest and recovery. Stress, recovery, stress, recovery–when calibrated to exhaust an athlete’s resources, but only just, and then replenish them, the process can expand the productive capacity of a broad range of cells in the athlete’s body.

What the scientists studying toughening have found is that a somewhat similar process of challenge and psychological loading followed by recovery can tune our brain and nervous system so that we too approach stressors with resilience and an optimal mix of hormones, neuromodulators, and nervous-system activation.

Is there anything we can do once exhaustion, fatigue, anxiety, or stress have set in? To answer this question we must bear in mind that these conditions are messages sent from our body telling us what actions we should take, and we need to understand what they are saying. Quite often, though, we misunderstand these messages. A telling example can be found in our understanding of mental fatigue. Common sense tells us that it is a state of exhaustion, in which we have quite simply run out of energy, like a car running out of gas. The recommendation that naturally follows is a rest or vacation to replenish our energy reserves. Exhaustion of this kind certainly occurs. Run a marathon, and chances are you end up in a state of exhaustion; pull an all-nighter, and chances are you need some sleep. But more often than not, this is not the cause of mental fatigue. Often, mental fatigue disappears if we merely change activities, and that would not happen if we had exhausted our fuel.

A recently developed model in neuroscience provides an alternative explanation of fatigue. According to this model, fatigue should be understood as a signal our body and brain use to inform us that the expected return from our current activity has dropped below its metabolic cost. The brain quietly searches for the optimal allocation of attentional and metabolic resources, and fatigue is one way it communicates its results. If we are engaged in some form of search and have not turned up any results, our brain, through the language of fatigue and distractibility, tells us we are wasting our time and encourages us to look elsewhere.

The cure for fatigue, according to this account, is not a rest; it is a fresh task. Support for this idea comes from data showing that overtime work does not in itself lead to work-related illness such as hypertension and heart disease; these occur mainly if workers have no control over the allocation of their attention. Applying such a model could benefit workers and management alike, for more flexibility in choosing what to work on, and when, could reduce worker fatigue, while management might be delighted to find that workers may be just as refreshed by a new assignment as by a vacation. This model of fatigue provides a good example of how understanding a bodily signal can alter the way we deal with it.


Novelty may thus prove rejuvenating when we are battling fatigue, but under other circumstances it can turn toxic–when we are trapped, for example, in a state of chronic stress. If we return to chronic stress and look at the influence of novelty in this condition, we can find another example of how we frequently misunderstand the source of our problems.

In a novel situation we do not know what to expect, so our body mounts a preparatory stress response. That much is perfectly understandable. What is less obvious is that it does not seem to matter whether the novelty is welcome or dreaded, for either can exacerbate chronic stress. This conclusion emerged from a study by two psychiatrists who compiled a list of life-changing events, known as the Holmes and Rahe Social Readjustment Rating Scale, which they used to predict future illness and death. They found that all the obvious stressors, such as divorce, the death of a spouse or financial difficulties, predicted a heightened risk of illness and death. But also high on their list were more welcome changes, such as marriage, the birth of a child, a change of job or, incredibly, outstanding personal achievement. While these events were no doubt welcome, they added novelty to the lives of the recipients, and that could later take a toll on their health. Our complete unawareness of the damage being inflicted on us at such times is one reason hypertension and heart disease are called silent killers.

Familiar voices and happy faces let our brain stem know that fight-or-flight is not needed. If you are blessed with a calm family and friends whose fortunes are uncorrelated with your own, it can help enormously in times of stress just to look into their faces and listen to their happy voices, rather than staring at your BlackBerry, gnawing on your fingernails and ruminating over past outrages.

Once we come to understand the signals our bodies send us, including fatigue and stress, there is a great deal we as individuals can do to toughen ourselves against their ravages, and we as managers can do to minimize their impact. It is wise and far-seeing managers who put health and stabilized risk preferences at the top of their company’s agenda.

From The Hour Between the Dog and Wolf, by John Coates. Published by arrangement with The Penguin Press, a member of Penguin Group (USA), Inc. Copyright (c) John Coates, 2012.

[Image: Flickr user US Air Force]