Fatigue and Mental Toughness 197 and it continues to be associated with poor performance, accidents and ill health. In response to this enduring and real world problem, there is a global academic interest in all aspects of fatigue, which can be categorized into the following areas of research: 1 Understanding the development of the fatigue state and what makes people tired. What are the conditions in the workplace, for example, that make people tired? How are people affected by factors such as workload, exercise, autonomy, social support, noise and lighting? Exploring the personality factors that can moderate the state. Is the development of fatigue different in people who are high in traits such as mental toughness, trait anxiety, or conscientiousness? The development of tools and techniques for measuring changes in fatigue. Can questionnaires adequately measure levels of fatigue? Are there any reliable physiological changes that can be used to estimate or even explain fatigue? Can we measure differences in distinct types of fatigue, such as mental, emotional and physical fatigue? Understanding and minimizing the consequences of fatigue for performance (in the short term) and for health and wellbeing (in the