Validity of Ergograph as Measurer of Work Capacity 3 



obtain a livelihood until they have attained considerable skill. 

 Without practice they can not do anything at all. The training 

 to which race horses, prize fighters, and professional athletes 

 must submit before they enter contests is essential both from a 

 sentimental or sporting and commercial standpoint ; they must 

 be made to reach the highest level of practice effect of which 

 they are capable in order to satisfy our pleasure in seeing ani- 

 mals and men contend and strive with one another in rivalry and 

 because the strength, skill, and agility developed in this way 

 come to have commercial values as they formerly had selective 

 values in biological history. 



Empirical Observations upon Practice. — Practice is not a sim- 

 ple phenomenon ; it manifests itself in different ways. One may 

 easily discover a variety of effects which exercise will have upon 

 the individual who practices himself in any line with vigor and 

 persistence. Naturally the results are not the same or uniform 

 in degree. Certain effects are greater and more obvious in one 

 kind of work than in another. The first and probably the most 

 important condition brought about by exercise is inurement to 

 the task. This is a process of hardening whereby the tissues and 

 skin which at the outset were rendered inflamed and bruised by 

 the physical exercise become calloused and give rise no longer 

 to the painful sensations which were experienced during the first 

 exercise. Want of inurement results in a greater or less degree 

 of muscular soreness and stiffness. A single unusual exercise 

 of any kind, if it be at all violent, has this effect. This soreness 

 and stiffness are probably due to small lesions of the tissues 

 through the rubbing and twisting of muscular and tendonal fibers 

 about one another which are followed by local inflammations. 

 Lagrange 1 attributes this condition to the retention within the 

 muscles of obscure waste products. A different hypothesis seems 

 to us more probable. The muscles and tendons lie contiguous 

 to one another in the members and when their positions remain 

 unchanged toward one another for considerable periods, as they 

 do at times when exercise is not taken, adhesions grow between 

 them as in all other tissues. Now when exercise is taken, the 



1 Physiology of Exercise. Appleton & Co. 

 6 8l 



