HOW EXERCISE AIDS THE BATTLE OF THE BLOOD
The question of breathing properly is intimately bound up with the question of exercise. The best of all exercise is play. All games in the open air which a person takes part in for the love of them far surpass the cleverest and most scientific sets of rules which physiologists have ever evolved. Unconscious performance of all the functions of the body is the ideal of hygiene. Exercise aids the battle of life within us in a direct manner. Exercise breaks down worn out tissue, making room for new and healthy tissue. It increases the rate of oxidation or burning up of fuel within us, and this in its turn enables the body to get rid of waste of material. Exercise also increases the strength and endurance of the muscles and fibres.
When muscles become weak, they relax and allow various portions of the body to drop into positions which are not only ungraceful, but are decidedly injurious. When the muscles are not used and become flabby, the shoulders get rounded and drop forward through the weakness of the muscles which are intended to hold them back in position. The ribs which form the framework of the chest not being properly sustained by the muscles attached to them, gradually fall inward, thus flattening the chest, and compressing the lungs. There is a very close connection between gracefulness of carriage and sound bodily health.
The person who lounges, or slouches, be it ever so picturesquely, does so at the expense of the body. Proper exercise will prevent these physical defects, and will remedy them in most persons who have not yet attained middle age. Even in advanced years, say the physiologists, much may be done to correct these physical deformities by properly directed and systematic exercises.