Nowadays, due to the influence of economic globalization, workers have to work faster and harder than ever under high pressure induced by their managers. Moreover, the necessity to increase productivity and flexibility resulted in longer hours of work and shorter rest periods followed by the irregular working time. One of the consequences of this workload is fatigue (1). Fatigue is one of the most important problems affecting several aspects of human life (2, 3). It is a serious issue in transportation and industrial safety studies (4). Reduced levels of performance (5, 6) and motivation, disability