CHAPTER II. 



THEORY OF EXERCISE. 



Definition Exercise in Relation to Health and Development Rest Fatigue 

 Nature and Duration of Healthy Exercise. 



DEFINITION. 



EXERCISE may be defined as " exertion or labour of the body 

 for purposes of health or development of the natural powers " 

 ( Lloyd 's Encyclopedic Dictionary); and work, as exercise 

 undertaken for purposes extraneous to the horse. In training, 

 the term " work " is often used for " exercise." 



EXERCISE IN RELATION TO HEALTH AND DEVELOPMENT. 



In writing of exercise under this heading, I assume that 

 the bodily exertion is not carried to an extent which would 

 produce fatigue. 



As the animal body has been evolved under conditions of 

 frequent movement, exercise is necessary for maintaining it 

 in health, that is to say, in its ordinary condition. In other 

 words, as " the function makes the organ," the existence of an 

 organ is dependent on the exercise of its function, as we may 

 see in cases of paralysis. For instance, when certain muscles 

 of the larynx suffer from the form of paralysis which causes 

 " roaring," they gradually waste away, and at last become 

 converted into fibrous tissue. Exercise is therefore needed 

 for maintaining the balance between bodily waste and bodily 

 repair. The effect of the exercise of the limbs is not confined 

 to the muscles of movement and their adjuncts (tendons, 



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