If a man needs certain muscles specially strong for his work, his work will develop them for him. Otherwise they are of little use to him, and he had better conduct his exercises on a sounder principle. [Sidenote: Object of exercise.] The main object of physical exercise is to keep the whole body fit. In choosing suitable ones, therefore, it is necessary to select those which call upon all the muscles of the body without any undue strain upon any particular set. If any one group is over-used there will come a time when they will begin to waste away. It is well known that in certain occupations which throw great strain upon any one part, such as the arms in the case of porters, who have to be lifting heavy loads constantly, the muscles of these regions enlarge enormously at first, but often degenerate after a time, until at last the limbs in question may be reduced almost to skin and bone. [Sidenote: Swedish exercises.] The best form of exercises for purposes of general health are those known as Swedish. No dumb-bells are required, though many people find it easier to practise them if they have a piece of wood in each hand. The number of systems included in this category is legion, and people are often perplexed to know which one to choose. Some friend recommends one set, then another comes along and says that he has derived great benefit from a different set, and a third strongly advocates some other. The fact is there is no advantage in any one over the rest. All are equally efficacious; the great point is to do exercises of some sort. You can easily plan out a set of your own, which will do quite as well as any other. Whichever are chosen, it is well to do them gently at first, and for a short time only, gradually increasing them as you become more accustomed to the movements. A good selection to start with is as follows. Stretch out the arms in front, with the finger-tips touching those of the opposite hand. Swing them slowly backwards as far as they will go. Stretch them out again in the same way, and try to touch the toes, keeping the knees straight. Place the hands on the waist and bend the body forwards as far as possible and also from side to side. Lie on the floor and raise the body without the aid of the hands and with the knees stiff. Stand erect and raise one leg slowly, balancing on the other foot. A few simple exercises such as these are quite sufficient to keep the whole system in good order. Complicated or difficult ones are never necessary. The one great point, more important than all else, is to attend carefully to the breathing while making the movements. Take deep, slow breaths, expanding the chest fully and exhale slowly, always breathing through the nose. If you get out of breath you are either doing the exercises wrongly or breathing in an incorrect manner.