"Exercise develops our muscles."

"Sleep is rest."

Few will quarrel with these statements, and yet they are only half-truths and therefore misleading.

We observe that a Marathon runner develops powerful leg muscles, and conclude that Marathon running directly develops leg muscles. This does not logically follow.

Actually, Marathon running wears out leg muscles, just as using a motor-car wears it out. At the end of his race, the runner, having lost several pounds in weight, often collapses as he reaches the tape, and has to be carried off the track. Clearly his muscles are worn out by the exercise, just as the parts of the motor-car are worn out by use.

But whilst the motor-car cannot maintain or repair its worn-out parts and these have to be replaced, the body can and does maintain and repair its worn-out tissues.

This maintenance and repair involve work which can only be done efficiently during sound sleep. Hence, sleep is fundamentally work and not rest, although the efficient performance of work of repair during sleep presupposes the interruption of physical activities not connected with repair. Like any other work, this work of repair which involves elimination of toxins, rebuilding of cells, and development, costs energy. Probably it costs us more energy to repair our bodies than it costs us to use them, just as the machines that make the many nuts and bolts and other countless parts of a motorcar spend more horse-power per hour making them than we could ever spend driving it.

The chief characteristic of sound sleep is, therefore, that it promotes sound repair work.

Most of us would agree that its second most important characteristic is unconsciousness, but that is only partly true. We have all experienced long nights involving eight or more hours of unbroken unconsciousness and awakened from them not only unrefreshed, but feeling less vital than on going to bed; and we have also risen considerably refreshed after an hour's rest during which we had not completely lost consciousness.

This must not be taken to mean that unconsciousness is of no value, but merely, that some repair can be efficiently done consciously, and that unconsciousness alone does not guarantee the efficient performance of any repair.

Thus arises the problem: Can the best work of repair be done consciously?—a problem which this book attempts to solve.

Whilst Marathon running does not directly develop the runner's muscles, the fact remains that the Marathon runner does develop powerful leg muscles, and we must conclude that there is a connection between the two facts, however indirect it may be.

The repair and development work of sleep is the connecting link between Marathon running and leg development. This is how it operates.

Preparatory to his Marathon race, which is to take place on a Saturday afternoon, our runner, his training being finished, spends a very quiet Friday. He retires to bed early and in the circumstances very little work of physical repair has to be done during his night's sleep.

On the Saturday afternoon he runs and wins his race, collapsing at the end of it. He has lost several pounds, feels utterly weary, rests for a while, takes some nourishment, and then retires to bed, faced with the necessity of doing a considerable amount of physical repair and development during his night's sleep. On the Sunday morning he wakes up and finds that the work of repair and development has been done.

The problem arises: Does the exercise taken induce the doing of specialized work of repair exclusively by the material method of fatiguing the body and loading it with toxins, or does it induce this work by making an impression on the runner's subconscious mind which is thereby stimulated to initiate and control the required work of repair? Is the work done purely mechanically, is it an intelligent process, or does it combine the two methods?

I shall offer the reader a solution of this problem, but meanwhile, the fact remains that although the specialized work of repair and development that is done on the Saturday night is only undertaken because of the Marathon race, it can only be performed during sound sleep. This leads us back to our fundamental problem: what does sound sleep involve, and what can we do to secure it?

Sound sleep is work of repair done within your body by yourself, although you may remain completely unconscious of the part you are playing, it is done by yourself just as much as any other work you do, although it is done subconsciously. As it is probably of more importance to your general welfare than any other work you may do, you should take at least as much care and trouble to prepare and train for it as you do for any other important business.

This preparation and training must be threefold, for you know that in any work you do three elements play their parts, your body, your nerves, and your mind; just as in the best motor-car the car, the petrol, and the driver play their parts.

If you wish for sound sleep, you must, before you allow yourself to lose consciousness, make certain—

(1) That your body, the most wonderful machine ever made, is in such a mechanical condition that you can do your work of repair efficiently, that is, at the lowest possible energy cost for the amount of work done.

(2) That you have stored up enough energy in your nervous system to enable you to do your work of repair, and

(3) That your mind is in such a state that it will not hinder you in your work of repair, but will subconsciously promote it after you have allowed yourself to lose consciousness.

I shall deal in turn with what you must do with your body, nerves, and mind, before you allow yourself to lose consciousness, if you wish to obtain sound sleep. I cannot emphasize sufficiently that you must do these things before you allow yourself to lose consciousness. The gravest mistake that all sufferers from insomnia, in all its forms and degrees, invariably make, is to seek unconsciousness first and foremost, irrespective of whether they have secured beforehand, the body, nerve, and mind conditions that are indispensable to sound sleep. Compared with these conditions of body, nerve, and mind that make for sound work of repair, unconsciousness is relatively unimportant. It is more refreshing to lie awake for hours in those conditions than to be unconscious without them for the same number of hours.

In short, give up bothering about unconsciousness, and concentrate on getting the right conditions for efficient work of repair, and sound unconsciousness will come to you naturally.