7 Life and Health 



done. What may be excessive for one person might be 

 beneficial to another. 



Breathlessness is, perhaps, the most common effect 'of 

 undue exertion. Let a middle-aged person, who is out of 

 practice, run even a short distance, and he is soon troubled 

 with his breathing. He pants, and his strength gives out. 



FIG. 39. A Well-Equipped Gymnasium. 

 (From a photograph.) 



His chest, and not his legs, has failed him. He is said to 

 be "out of breath." 



The heart is often overstrained during violent exertion, as 

 in lifting a great weight. Certain forms of heart disease 

 are common with those whose occupations involve severe 

 muscular effort, as professional athletes and oarsmen. 



100. Results of Excessive Muscular Movements. The 

 excessive repetition of muscular movements may lead to 



