Page:Athletics and Manly Sport (1890).djvu/159

134 is not to strain but to strengthen. Heavy dumb-bells strain; light ones strengthen.

"The effects of exercise," says an English medical authority on training, "are twofold: on the one hand a stimulus is given to the action of the heart and lungs, which enables the blood to be more thoroughly oxygenated and more rapidly circulated; on the other hand, there is an expenditure of force accompanying the increased activity of the organic changes. Exercise strengthens the parts exercised, because it increases the nutrition  of those parts. When any organ or muscle is inactive, the circulation in it becomes less and less; the smaller net-work of its blood-vessels are empty or but half filled; the streams gradually run in fewer channels, and the organ, ceasing to be thoroughly nourished, wastes away. When the organ is active all its vessels are filled; all the vital changes, on which depend its growth and power, proceed rapidly. The force expended is renewed, unless the expenditure has been excessive, in which case there is a disturbance of the mechanism, and depression, or disease, results. . . . The advantage of exercise to a student, politician, or any other brain-worker, is that it lessens the over-stimulus of his brain, distributes the blood more equally, calling to his muscles some of those streams which would impetuously be rushing through his brain."