ABSTRACT
The stress of business and of professional problems to be solved, and the worries of making ends meet, keep them at best balancing on the edge of fatigue. The causes of fatigue are chemical conditions resulting from changes within the organism. Since fatigue expresses itself in the tissues and organs of the body, the vigor of these organs is evidently an important matter; and any means of increasing their endurance has psychological significance. No apology, therefore, is necessary for referring to muscular exercise in the psychology of the day's work. Physical exercise as a means of acquiring resistance to fatigue has received too little attention, and the value of medicine has been overestimated. "It is well known that a man 'in training' has greater endurance than one who attempts exertion without previous systematic exercise or training. Training consists, among other things, in producing resistance to fatigue products.
