In more than 100 years of the history of human fatigue study, there had been proposed several study methods, the first of which was named the physiological entity theory of human fatigue. This theory was established on the basis of results of physiological experimental studies at the beginning of the 20th century.
It was asserted in the theory that human fatigue should be physiologically defined and assessed, depending on physiological mechanisms on accumulation of metabolites such as lactic acid due to activity, depletion of substances necessary for activity and so on.
The theory hypothesized that an industrial worker's fatigue was a condition caused by work, in which his/her work capacity was diminished, inevitably resulting in a decrease in work performance, and that the diminution of the work capacity should be due to the functions of the physiological mechanisms.
The purpose of the present paper was to make clear the reason why it had been found out in the history of workers’ fatigue studies that the physiological entity theory was not applicable to the studies, with making reference to Muscio (1921) and Browne (1954).
The present paper discussed that studies on workers' fatigue had adduced evidence that when they continued to work in different types of tasks, their work performance increased or decreased, affected by psychological functions such as motivation, need and emotion. It was also discussed that the studies had proved it effective in reducing their fatigue to take measures to decrease long hours of work, to introduce adequate rest pauses, to improve work environmental factors such as illumination, temperature and noise, to make better design of a machine and equipment in a workplace, and so on.
The author of the present paper admitted that at the end of the first half of the 20th century, it was proved that the physiological entity theory of human fatigue was not able to assess work performance of industrial workers in actual workplaces, and therefore, that it was invalid for the explanation of the cause of their fatigue.
We evaluated the impact of a health education program carried out for male employees, employed at small and medium-sized transportation office, on the knowledge and behavior modification of the subjects in terms of weight control and reduction in the incidence of metabolic syndrome.
There were effects to encourage the practice of their possible implementation items of efforts on the eating habits and lunch intake; however, it is difficult to bring about changes in the weight and metabolic syndrome related indicators through short-term health education programs. To spread health education to those with fewer opportunities, it is important for the senior management to recognize the need for health management of employees and the occupational health and safety personnel, and to consider the programs in small-sized workplaces with minimum burden on participants.