THE MUSCLES AND HEALTH
=Making the Muscles Strong.=--No persons use all of the five hundred
muscles in the body every day. In slow walking only about twenty
muscles are used, while in running more than four times that number
are called into action. Muscles which are not used get lazy and weak.
Every time a muscle is made to act the blood vessels enlarge and bring
to it more blood to supply food. The more food the muscle has the
stronger it grows. The right arm is used more than the left in most
persons. This makes it so much stronger that some boys can lift
twenty-five pounds more with the right arm than they can with the left.
=Using the Muscles keeps the Body Well.=--All muscles must have more
blood when they are used so that the heart is made to beat faster and
stronger by exercise. In this way its valves and walls become able to
do more work. Such a heart not only does its work better in a well
person, but is able to keep pumping when the body is weakened by
disease. Many persons die because the heart gets too weak to push the
blood through the body.
In all the little spaces between the muscles and parts of other organs
is some watery part of the blood containing much waste given off from
the tissues. Moving the muscles presses on this watery waste in such a
way as to move it along into the blood channels. It then can be cast out
of the body by the lungs and other organs. One reason why we feel so
good after exercise is because the poisonous waste has been taken away.
No one can remain well very long without taking exercise. Children as
well as older persons should enjoy one or two hours of outdoor play
every day.
[Illustration: FIG. 85.--Various ways of exercising the muscles to
keep the body well.]
=How to exercise the Muscles.=--Outdoor games give the best form of
exercise. Tennis, baseball, cricket, rowing, and swimming are sports
which bring nearly all the muscles into use. Every boy and girl should
learn to swim. It is dangerous to go swimming alone or to swim in
deep water. Cramp may seize the muscles at any time, so that the limbs
cannot be moved. Hundreds of persons are drowned every year by
venturing in deep water.
Taking care of the yard and garden and helping with other work about
the home is one of the best ways of getting exercise and at the same
time doing some good.
=Special Kinds of Exercise.=--A room with ropes, swings, and machines
in it for exercise is called a _gymnasium_. Under the direction of a
teacher the pupils can get quickly just the right kind of exercise to
strengthen the weak parts of the body and keep every organ in health.
The muscles oftenest neglected are those of the chest. Every one
should keep his chest full and round by swinging the arms and
_practicing deep breathing every day_.
=Danger from too much Exercise.=--Lately it has been learned that very
violent exercise for more than a few minutes often injures the heart.
The running of many races until you are all out of breath or much
jumping of the rope is likely to strain the heart. It is always
harmful to urge the body on until it is completely tired out.
=Alcohol makes the Muscles Weak.=--In the year 1903 two learned men in
Switzerland spent much time to determine whether alcohol helped
persons do more work. They tried more than two hundred experiments
with men to whom they sometimes gave wine and sometimes food, and
sometimes both were given together.
The results of these tests showed that when wine was given alone, the
man's ability to do work was increased for a short time, but later he
could not do so much work as when he had taken no wine. When the man
took both food and wine, he could do only about nine tenths as much
work as when he took food alone.
The most careful tests by other persons show that whisky will not help a
man do more work, lift a heavier weight, or shoot straighter. In fact
little or much whisky makes him less able to do any of these things.
=Beer makes the Muscles Lazy.=--Doctor Parkes of Netley secured two
gangs of soldiers to do the same kind of work. He allowed the first
gang to drink some beer, but the second gang were not allowed to have
any. During the first hour the beer gang did the most work, but after
that the temperance gang did far more work during the entire day. The
next week beer was refused the first gang and given to the second. The
beer helped the second gang do more work than the first one for nearly
two hours, but after that they did much less than the first gang.
This shows that men who wish to do their best work during the entire
day should not use beer.
=Tobacco and the Muscles.=--Many experiments and studies have shown
that the body cannot do its best work when even very small amounts of
poison are taken day after day. The poison in tobacco is believed to
weaken the muscles so much that no man on a football team in any of
our large colleges or universities is allowed to smoke or chew during
the season. Persons training for any contest where much strength is
required do not use tobacco in any form.
=Tobacco prevents Growth of the Muscles.=--The moderate use of tobacco
by men has but little effect on the muscles. It may cause them to tire
a little more easily when doing very hard work. Tobacco poison does,
however, show a marked effect on the muscles of the young.
Very careful measurements made at one of the large universities showed
that the boys who did not smoke grew one tenth more in weight and one
fourth more in height than those using tobacco regularly. This slow
growth in tobacco users is partly due to the fact that tobacco makes
the muscles in the walls of the blood vessels squeeze together so as
to shut off some of the blood from the legs, arms, and other parts, so
that they get too little food. Tobacco may also cause less food to be
digested for the use of the body.