Effect of fatigue on the appearance of errors in the execution of a complex manual task – research in the table tennis domain

Although the problem of human fatigue is widely researched, on the basis of detailed research of the literature that was assisted by aggregators such as EBSCO Discovery Service it was determined that there was no paper that previously exclusively dealt with the effect of physical fatigue on the appearance of errors during the execution of a manual task. There are certain papers that deal with the issue of the influence of physical fatigue on motor activity, but they do not take into account in a quantitative way the errors in manual performance that occur as a consequence of fatigue. Besides, some of the papers on similar topics do not quantify fatigue in an adequate way (for example, by using a scale for subjective assessment that is not formally intended to measure fatigue). Due to that, it may be considered that this is the first paper in the world that has been entirely dedicated to the problem of the influence of physical fatigue on errors in the performance of complex manual tasks, such as those in the domain of table tennis. In this research, four intensities of physical activity were chosen to induce fatigue: light, moderate, hard, and very hard. Statistical testing revealed that only when fatigue was induced by light physical activity the number of serving errors was not significantly higher than in the resting state, while fatigue induced by moderate, hard, and very hard physical activity resulted in a statistically significant increase in serving errors. In addition, in this paper for the first time it was calculated the reliability of serving as a ratio of the number of successful serves and the total number of serves. It was found that the reliability of serving (as a complex manual activity) in table tennis decreases by 24.67% overall in the fatigue condition, and specifically by 3.33%, 30%, 28.47%, and 35% when fatigue is induced by light, moderate, hard, and very hard intensity of physical activity, respectively. Having in mind the aforementioned, fatigue should be taken into account when planning and executing intricate and precise manual tasks, such as those in sports, medical procedures, military operations, construction and similar.