Of the substances supplied to the muscles by the blood, oxygen is one the want of which is soonest felt. The muscle contains within itself a certain store of oxygen, but one which is by no means equal to the oxidizable substances. The muscle’s activity is dependent, to a great extent, on the character and force of the blood-flow. It must be clear of waste products, and contain, as well, sufficient oxygen to keep up continually a renewal of energy.
From what has been said, it will readily be seen that the result of a muscular task which an athlete wishes to perform, will depend primarily on his muscular bulk and on the conditions of these muscles and the rate at which he expends his capital; the test of his endurance will depend upon the condition of the other parts of his body and how rapidly they will carry off the quickly formed poisonous products and supply fresh ones.
A large number of the lesser pugilists have died in the ring the last ten years. Scarcely one of these deaths was directly due to the force or severity of the blows struck, but because the fighters were “out of condition.” The writer, himself, once had an opponent in the amateur ring whose condition was so plainly unfit that he refrained from exerting forceful energy, but let the man poison himself, when a gentle cross-counter laid him out. He literally beat himself.
What I have said about self-poisoning refers also to the nerves and brain. As the muscles work faster, so do the central nerve cells which send the stimulating impulses to these muscles. These latter cells become fatigued sooner than the muscles. This is a grand feature of physiologic economy; for, did not this condition exist, the muscles would work themselves to pieces—run wild, like an uncontrolled engine.
The muscular differences noted in individuals are in reality the difference in the nerve cells, the actions of the muscles indicating the activity of the central nervous system. When the muscles are being exercised the nerve cells indirectly determine the muscular activity.
From the above statement it can be seen why one with exhausted nerve cells should avoid exercise. The nervous system should be at rest. For example; if a youth is recovering from some severe illness—typhoid fever, let us say—he should not at first try to get back his muscular strength by self-exercise. The muscles need blood sent to them to grow and regain their former elasticity, but the nerve cells required for all this must have a rest. How is it to be done?
By the exercise of another person’s nerve cells. That is, the muscles should be massaged by some strong man. As the nerve cells gradually come to their full activity again, then the youth may commence gradual exercises on his own account.
It is the general impression among athletes that exhaustion and “loss of wind” are due to the inability to consume sufficient oxygen and exhale rapidly enough carbon dioxide. When the muscle is moving rapidly and forcibly, it is true that it demands more oxygen and gives off to the blood more carbon dioxide than when at rest. When a man is running as fast as he can make his limbs move, he is able to keep up the pace but for a short distance, unless, like the hunted hare, he runs to death. On account of the forced and rapid muscular action in this case the poisonous materials are thrown into the blood, to be carried to all parts of the body—muscles, nerves, brain. The heart is affected by this poison through the nerve cells controlling this organ; the muscles of respiration are similarly disturbed. The panting, distressed efforts of breathing, sidelong tumbling and final semi-unconsciousness of the hunted stag or hare are good examples of acute self-poisoning ending in death. It is just as much a case of poisoning as would be a case of gas poisoning; the only difference being that in the first case the gas is manufactured in your body, in the other case, outside and you breathe it in.
One of the main “clearing houses” of the body, by which the blood is constantly cleared of much of its poisons, is the liver. The minute cells of this organ each have their individual work to perform in transforming the poisonous material into harmless substances. The cells of this “clearing house” are delicate little organs, and will not stand abuse. All habits having a tendency to cause dyspepsia—eating rapidly, eating indigestible food, constant and intemperate use of alcohol or the use of tobacco in the youth—disturb the normal work of the liver. Hence, one of the first aims of a boy who desires to be a strong man—and what boy does not have this admirable aim?—should be to keep the liver in the best possible condition. Any clogging or disturbance of the ordinary work of the liver prevents the blood from being in a pure state. All parts of the body will show distressing symptoms of fatigue and exhaustion if the little cells of the liver have become diseased or useless through intemperate living and ignorance of the duties belonging to each separate organ of the human body.