EXERCISE FOB ELDERLY PEOPLE. 773 



rioration. It is a warning which it would "bo a grave imprudence 

 not to heed. 



The elderly man should therefore give up all exercises of speed 

 like running, and all those in which energetic efforts are added to 

 speed, like rowing in matches. We see men of exceptional powers 

 of resistance continuing to practice exercises of speed till they are 

 forty-five years old ; but it is well to know how indulgence in cham- 

 pionship feats late in life usually ends. Many affections of the 

 heart are consequences of exercises or labors that exaggerate the 

 effort of that organ in men who have reached maturity. The cen- 

 tral organ of the circulation can not be subjected without danger 

 to excessive work, when its play is not seconded by the elastic force 

 of an unimpaired arterial system ; when it is partly deprived of 

 the re-enforcement which is lent it by these contractile channels, 

 the office of which in the circulation of the blood has been hap- 

 pily described by giving them as a whole the name of the " pe- 

 ripheric heart." 



All men who employ animals in work know how their speed 

 falls off with increasing age. Race-horses are withdrawn from 

 the track shortly after they have arrived at the full possession of 

 their force ; they are still good for competitions in bottom, and 

 are capable for many years yet of doing excellent trotting service, 

 but they can not run in trials of speed. Man's capacity to run 

 likewise decreases after he has passed thirty years ; and the pro- 

 fessional couriers who are still seen in Tunis, running over large 

 distances in an incredibly short time, are obliged to retire while 

 still young. Those who continue to run after they are forty years 

 old, all finally succumb, with grave heart affections. 



There are some persons who preserve to a relatively advanced 

 age the faculty of enduring violent exercises, and of contesting 

 with young persons in quickness of muscular work. Not long 

 ago two men, one forty-five and the other forty-eight years old, 

 contested in the regattas on the Seine and Marne. Their craft 

 was called the old men's. Few oarsmen continue to row in races 

 after they are thirty-five years old. But those whom we are 

 speaking of, though long past the usual age for retiring, have 

 often gained the prizes which competitors twenty years old dis- 

 puted for with them. These exceptions, however, do not depre- 

 ciate the force of the principles we have just explained. They 

 prove that one rnay be young in spite of his years, and that the 

 chronological age does not always agree with the physiological 

 age. While some persons are in full organic decadence at thirty- 

 five years, some others may not yet, at fifty years, have undergone 

 the modifications of nutrition which are the beginning of old age. 

 The capacity of a man for violent exercises is determined by the 

 more or less complete integrity of the arterial tissues. Men who 



