Principles of Public Health / A Simple Text Book on Hygiene, Presenting the Principles Fundamental to the Conservation of Individual and Community Health

by Thomas Dyer Tuttle

[CHAPTER XII]
REST ESSENTIAL TO HEALTH

Why exercise is necessary

Exercise is necessary to make our bodies grow and become strong. If we stayed in bed all the time, our muscles would not grow and we could not even walk. If we did not exercise them, the cells in our brains would not grow and we should not know anything. Every part of our body must have exercise, that is, each part must do some work every day. If we used only one part of the body and did not give the other parts any work to do, only the part that we used would grow, while all the rest of the body would be small and weak.

Proportion of rest required

While every part should do some work each day, the whole body needs also to have a proper amount of rest. Even the heart, which seems to be working all the time, must rest. It rests between each beat. The muscles with which we breathe rest between each breath. Every person must have a certain amount of rest each day. A man should have at least eight hours' sleep in every twenty-four hours; boys and girls should have from nine to ten hours' sleep in every twenty-four. It is only while we are sleeping that we have complete rest.

Effect of overwork

Everybody should have some work to do. Boys and girls should learn that work is a part of life, though they should not be expected to do too much. They should not be required to get up at four o'clock in the morning and work until eight, then go to school until four in the afternoon, and then work again until dark. They cannot do this and keep well. Such children will surely neglect their lessons and will fail to keep up in their classes. It is not the children's fault, but the fault of the people who give them so much to do outside of school.

Sometimes bright children fall behind in their classes and seem to be sleepy during school hours. Very often these children do not have to do any work at home, but play all the time they are out of school. We usually find that these children not only play all the afternoon, but also go to parties at night and often stay up until midnight.