ments, hydrotherapy, and hygiene; all these involve exercise in a fundamental sense, and are of great therapeutic utility, even in febrile states, where exercise of the skeletal muscles is absolutely contraindicated.
The professional and domestic occupations, recreations, and sports have been noticed in their relation to the hygiene of exercise, and it is desirable that these means, which are within the reach of such large numbers of people, should be more often utilized therapeutically. For this purpose it should be remembered that many exercises have a preponderating effect on certain organs.
"Rowing tells on the breathing organs; the work of dumbbells, and of other exercises where muscles are moved without progression of the body, tells most on the muscles themselves; and long pedestrian feats, with climbing, tell on the nervous system. In cycling, as in running, it is the heart and circulation that first give demonstrative evidence of important change of action" (Richardson).
Housework, chores, gardening, walking, climbing, cycling, running, swimming, and many other sports give just the kind of exercise that is indicated in certain conditions, due regard being had to the physiological effects of varying dosage. Oertel has shown how the simple exercise of walking may be adapted to sufferers from cardiac debility by prescribing the distance and speed, and the number and length of the rests, on definite paths graduated according to their slope. His interesting and original work has not only given a new direction to the treatment of certain cardiac affections, but is destined to have an important influence in establishing accuracy in the prescription of exercise. Whoever has studied the map of the environs of Reichenhall, Bavaria, prepared by Oertel for the application of his method, will acquire a vivid idea of what precision of dosing in exercise means. In this map the different paths suitable for the work are marked in four different colors, to indicate those that are nearly level, those slightly sloping, moderately sloping, and steep, and figures are placed along each route to show the space that should be traversed in each quarter hour. The locality itself is prepared for its remedial use by placing benches for resting at suitable distances, and by marking on certain trees near the path circles, colored to correspond with the map, to indicate the difficulty of that particular section. By systematic practice on the easier paths the heart and system are progressively trained and strengthened. Intelligent analysis may do the same work for cycling, horseback riding, and many other familiar exercises. In this way the dosage is practically reduced to a definite number of kilogram metres in a given time, and a step has been taken in placing the prescription of exercise upon a scientific basis.
