The New Zealand Railways Magazine, Volume 4, Issue 9 (January 1, 1930)
Note the physical and mental condition of factory operatives at “knock-off” time. The individuals exhibit a remarkable range in activity. There are some who are, apparently, “dog-tired,” there are some who seem reasonably fresh, while intermediate stages of fatigue between these extremes can be readily distinguished. Fatigue, as is generally defined, is the deadly enemy of both operative and employer. To the former it means the inability to enjoy leisure, while the latter realises that fatigue means a lessened output.
Scientifically, we are only now beginning to acquire precise knowledge about fatigue, but, even at the present stage of investigation, we know very little of the cumulative effects which seem so painfully evident in most industrial centres. What we do know, however, is that fatigue may be considered as a mental or as a physiological phenomenon.
Mentally, fatigue has been experienced by most of us. It comes as a feeling of tiredness or weariness, but it has a wide range of intensity, from sheer boredom to neurasthenia. Research in England during the war period, when factories were working at greatest pressure, showed only too clearly that fatigue at the most intense degree was responsible for the numerous cases of nervous breakdown. How far the mental state is the effect of the physiological condition it is not possible to say directly, as conflicting theories have been put forward by respective supporters with all the enthusiasm possible.
Physiologically, fatigue is much more easily recognised as a state of bodily exhaustion, a feeling of being “done-up” and requiring a rest. The explanation of this, too, is more easily given than that for the mental aspect. The state is brought about by the piling up of fatigue-toxins, which the blood cannot remove. These toxins are the residue of inorganic matter and used-up matter of the cells of the body. These chemical wastes are, in ordinary circumstances, immediately carried away by the blood, but if the blood stream becomes too heavily laden, the poison accumulates so that the individual requires rest to allow the blood to catch up on the job, as it were.