MOTION AND LOCOMOTION 115 



a street car, is certainly detrimental to the general health; though 

 the extremes of heat and cold to which we are subject often 

 render it unavoidable. 



For women during middle life the same rules apply: there 

 should be some regular but not violent daily exercise. 



In Old Age the needful amount of exercise is less, and it is 

 still more important to avoid sudden or violent effort. 



Exercise for Invalids. This should be regulated under med- 

 ical advice. For feeble persons gymnastic exercises are especially 

 valuable, since from their variety they permit of selection accord- 

 ing to the condition of the individual; and their amount can be 

 conveniently controlled. 



Training. If any person attempt some unusual exercise he 

 soon finds that he loses breath, gets perhaps a " stitch in the side," 

 and feels his heart beating with unwonted violence. If he perse- 

 vere he will probably faint or vomit, as is frequently seen in the 

 case of imperfectly trained men at the end of a hard boat-race. 

 These phenomena are avoided by careful gradual preparation 

 known as "training." The immediate cause of them lies in dis- 

 turbances of the circulatory and respiratory organs, on which 

 excessive work is thrown. 



