All kinds of exercise have one essential point to them—they produce a contraction of the muscles. As Ludwig and his disciples have shown, contraction of the muscles produces an increased supply of blood in them; more arterial blood being brought to the muscles, more oxygen and heat is generated through them, which results in a general increase of the process of oxidation.

When muscles are undergoing contraction impulses are conveyed to the splanchnic nerves, which are the regulators of the vasomotor system. Through the irritation of these nerves, the blood-vessels of the internal organs supplied by the splanchnics contract, and more blood is despatched to the periphery of the body. The capillaries of the skin will be dilated, and more blood will also be brought to the sudorific glands; these also excrete more water, which takes the form of sweat. Thus, by exercise that causes some exertion, abundant perspiration follows, by which means we can obtain the advantages we have mentioned in the chapter on the hygiene of the skin and kidneys; and it is for this reason also that we place this chapter on exercise immediately after the above-named one.

The essential point in these exercises is that a great part of the circulating blood will be brought to the periphery of the body, and thus the congestion of the internal organs will be prevented or relieved. Among these organs the kidneys will be benefited, but only in a preventive sense, for in inflammatory conditions of the kidneys, especially in the parenchymatous forms, all kinds of exercise should be avoided. Besides the kidneys and other organs, the heart also may benefit by exercise if such be taken in moderation. The greatest benefit, especially for those with a diseased heart, will follow exercises carried out in the form of Swedish gymnastics.

The originator of the Swedish gymnastic movements was Peter Ling, who gained great credit for himself and his country by the invention of this system, which has prolonged the life of many persons suffering from chronic ailments. In the Royal Central Institute for Gymnastics in Stockholm, and also in private schools in that city, many experts have been trained in these methods, and from thence they have spread all over the world, many coming to the United States, where Dr. S. Weir Mitchell introduced these salutary systems, and also massage.

Massage was known thousands of years before Ling’s time, notably in India, Java, and other countries of the Malayan race. Even the great Harvey knew the effects of massage, for he quotes the case of a man who, in consequence of an insult which he could not avenge, became so overcome with passion and rage that he fell into a strange disorder—suffering from extreme compression and pain in the heart and chest, from which he only eventually received some relief when his chest was pummeled by a powerful man—just as a baker kneads dough.^[240]

The essential thing in massage is the kneading of the muscles. We thus artificially increase the flow of the blood in them through the local irritation of the skin and the mechanical diffusion of the blood in the direction of the muscle. We thus produce artificial hyperæmia, not unlike the effects of a mustard plaster, and, in the same way as the plaster, we are also drawing blood from the congested organs, and especially from the engorged heart; thus we obtain a better distribution of the blood throughout the body and facilitate the action of the heart.

It has been shown by the experiments of Sir Lauder Brunton and Tunnicliffe that kneading the muscles increases circulation through them in the same manner as massage. They found that during such kneading the amount of venous blood which issued from them was sometimes diminished and sometimes increased; that just after the kneading was over the flow diminished (apparently from the blood accumulating in the muscles), and this diminution was again succeeded by a greatly increased flow. The clinical results are precisely what one would expect from increased circulation in the muscles, and cases apparently hopeless sometimes recover most wonderfully under this treatment.

By means of massage the functions of the heart can thus be facilitated, for massage mechanically diminishes the resistance of small capillaries to the oncoming blood-waves sent from the heart. It mechanically quickens the circulation of the blood through the capillaries by dilating them in a way similar to exercise (see, also, Chapter XVIII).

By certain massage movements applied to the exterior region of the heart—such as vibratory massage—this organ can also be favorably influenced; and by kneading, friction, and massage together applied to the periphery of the body, and by passive movements of the extremities, many cases of heart disease have been treated with good results, and premature death prevented. Still more thorough is the effect of such treatment if carbonic acid baths are used in connection with the above, as at Nauheim, for such baths stimulate the skin, which becomes better provided with blood. We have referred to the effect of such baths in a previous chapter on the hygiene of the skin and kidneys by means of bathing.

The Nauheim treatment affords good results in mild cases of arteriosclerosis, dilatation of the heart, and various other forms of heart disease.

Massage is also an excellent thing in chronic diseases of metabolism, as it helps the resorption of waste products and augments the processes of oxidation; in cases of gout, obesity, and also diabetes, it can therefore give very good results.

In the case also of healthy people who can afford to be massaged daily, vital functions can be rendered more active and youthfulness prolonged; and for those who do not possess facilities for being massaged by others, they can perform it themselves by friction, rubbing the body at rising and just before going to bed.

The Swedish movements can also be performed not only by free gymnastics, but also by the use of mechanical apparatus, such as that invented by Dr. Zander of Stockholm. These movements, combined with massage, also give good results in many of the above-mentioned ailments, but it would lead us too far to enlarge upon them here.

Much more strenuous for the body than Swedish movements and massage are the exercises of sports, a complete description of which would exceed the limits of the present work; but whether it be football, tennis, golf, athletics, or cycling, the great object in all is to easily create perspiration, by which the benefits described in the chapter on hygiene of the skin and kidneys are obtained. It goes without saying, that a diseased state of the kidneys excludes all kinds of violent exercise which require a severe bodily movement. By means of sport the processes of oxidation are also rendered more active, and thus obesity can be prevented and cured, and at the same time the waste products are more thoroughly consumed. Neurasthenic conditions, insomnia, etc., may be improved if the sport adopted does not lead to too great fatigue; otherwise they may be made worse. Taking into consideration, however, the conditions of the circulatory mechanism, sport is a two-edged sword. If undertaken in moderation all sport can improve our physical condition; but it may prove disastrous if reason be not exercised and it is indulged in to excess. By the strong muscular exertions referred to an irritation of the splanchnic nerves takes place, resulting in a high blood-pressure; more blood will pass with greater vigor through the arteries and capillaries, which, consequently, become dilated. If this occurs too frequently they will, as is only natural, lose their elasticity, in which case degeneration of the arteries and development of arteriosclerosis may follow.

When a succession of severe muscular exertions takes place an accumulation of blood occurs in the right side of the heart, and, as the right ventricle cannot empty itself, shortness of breath, and even death, may result. The left ventricle then becomes dilated, and such dilatation of the heart not infrequently persists for a long time, even in persons who have been in good health before undertaking severe exercises. If, therefore, the normally healthy may suffer from an irrational indulgence in sport, how much more fatal must be the results to those with heart or kidney complaints, and with degenerative conditions of the blood-vessels?

To persons of advanced age sport may be very pernicious, for here the elasticity of the arteries is wanting; they are more rigid, and consequently cannot so readily dilate. Overexertion in such cases may lead to the gravest results.

As those engaged in sport lose a large quantity of fluid, they soon feel thirsty, and so may be inclined to make up the deficiency of water in the blood by partaking of alcoholic beverages, such as beer, whisky, or wine; and if such are taken in large quantities, necessarily further dilatation of the heart and blood-vessels will result, as is usual from the frequent use of large quantities of liquids, not taking into account the mischief caused to the various organs by the alcohol. As a general form of exercise sport in moderation can be beneficial to the heart. Naunyn has shown that blood-pressure falls from continuous exercise, and Masey has also demonstrated this on galloping horses. The best form of exercise is walking or moderate climbing. Moritz has shown that after exercise the volume of the heart is diminished, and the rate of the pulse increased.

There are certain sports which do not require great bodily exertion, and these are, in consequence, less harmful to the heart. Take, for example, horseback riding, which produces a more or less accentuated rhythmic shaking movement of the body. In a particular style of riding called “the English trot,” the body rises and falls at regular intervals, which causes—as we noted in our own person—free perspiration; the circulation, especially in the abdominal organs and lower extremities, is also promoted. We consider riding to be one of the most beneficial kinds of exercise. We frequently note the healthy appearance of horseback riders (except jockeys, who are underfed in their training). A well-known member of the medical faculty in Berlin, a world-renowned specialist, was a great horseman. He took part in the last Medical Congress in Dresden, coming on horseback through the pouring rain from Berlin. Possibly his good health was due to the vigorous exercise of which he was so fond. By a strange irony of fate, this enthusiastic admirer of riding died in consequence of an accident caused by his automobile a short time ago.

In certain kinds of sport, such as riding and cycling, the greater possibility of accidents is a drawback, and in nervous individuals serious traumatic neurosis, and often diabetes, may sometimes develop, particularly in those cases where such people are descended from diabetic parents. We published a case of this kind some years ago. For such people this kind of exercise should be prohibited, especially in those descended from diabetic parents. Cycling has the additional drawback, according to Zunz, that from it fatigue is not so soon felt, and thus overindulgence may more easily occur.

Less injurious than sport, and much easier to be performed, is walking exercise. As walking on the level does not necessitate great exertion, unless performed rapidly, it can give good results if continued for a considerable distance. It is desirable to walk as much as possible, and never to use a street car or a carriage unless pressed for time; by this means health may be greatly improved. In walking especially the muscles of the lower extremities are contracted, and at the same time the circulation is improved, the more so, of course, in the lower extremities, but also in other parts of the body; and this is still more the case when we walk briskly. For those possessing a good circulatory mechanism, it is always advisable to walk briskly, thus indulging in a healthy and practical and muscular exercise; and for such, also, running for a few minutes several times daily is excellent, as perspiration can thus be created, whereby harmful products are eliminated from the body. This latter exercise is more suited to those living in the country, or if in cities, to those who have a garden or large yard.

It is advisable not to run too fast, as such would cause severe exertion with bad effects upon the heart; but if undertaken at all it should only be for a minute or so. Running at a moderate speed, breathing deeply and rhythmically at the same time, and with rhythmical, rather short steps, can be kept up even for eight to ten minutes without any particular harm to the circulatory system. Personally we used to do this, and often, when the thermometer stood below zero, without hat or overcoat, finishing thoroughly warm and comfortable. Standing still after running, when so attired, might lead to catching cold, but running out of the house and back again without stopping causes no such risk, even in a strong wind, as we have personally proven. Such running may best be done three times a day, before breakfast, dinner, and supper, as this running in and out of the garden is the best of appetizers, and is far more beneficial than drugs for those men and women who sit about all day and complain of want of appetite. Such running practice is only good for those who have sound blood-vessels, heart and kidneys. Deep regular breathing while exercising is also indispensable.

Walking up a hill will naturally require greater exertion than walking on the level, and may be more beneficial to the health than sports conducted to a similar degree. At first the blood-pressure will increase, but it will afterward decrease. Deeper respirations will have to be taken, so that a larger supply of oxygen will be brought to the lungs and tissues.

Climbing high mountains should be strictly forbidden persons suffering from disease of the heart and arteriosclerosis, for the greater exertion then required has often caused death in persons so afflicted. To prevent the bad circulatory effects of climbing it is necessary to breathe deeply and regularly, and this, indeed, should not be overlooked in all forms of exercises; even masseurs are unable to work properly unless they take deep regular breathing.

In mild cases of heart trouble, and even in more serious cases if applied judiciously, Oertel’s treatment of each day slowly walking up a steeper and steeper hill will give good results, giving good training for the heart-muscle. But this treatment should only be carried out under the direction of a competent specialist.

The great advantage of the various kinds of sport and of walking, climbing, and running exercise is that several other agencies can be combined with them that are very important in the treatment and prevention of the effects of old age. These are fresh air and sunshine. We think that the combination of the three agencies—exercise, fresh air, and sunshine—is the best and most necessary means for the preservation of youthfulness and for the prolongation of life.