No exercise that requires sudden violent effort, like fast rowing, or a hundred-yard dash in running, can be undertaken without serious effect to the heart. The Andean Indians will run, lightly and easily, at the rate of ten miles an hour, and keep it up for ten hours without rest, but you cannot induce them to make a short dash at high speed; they do not want to feel the warning thump of the heart.
In learning to run, breathe as in walking, keeping the body slightly bent forward, and the elbows gripped close to the sides. Under no circumstances start out by competing with any one, or by trying to run against time. Such a course will result in final failure, and may bring on a serious injury.
The jog trot is the thing to start in with. Try it for a week or two, and you will be surprised at the ease with which you can do it. At first a mile is long enough for a run. After a month you can do two miles without as much fatigue. Finally, if the gait be not too fast, you can keep it up for hours.
After you have mastered the jog, it will be time enough to quicken the pace into a run, not your swiftest run, mark you, but a run that you can keep up for a mile, with as little exhaustion as you did your first mile trot.
It is only by this slow, pleasant training, that you can ever learn to walk and run well, but when you have learned you will be paid for the effort, and then if the time comes to test your speed you will be ready to respond.
Jumping is closely related to running. It is an exercise in which boys delight, but which they seldom practice so as to achieve any skill.
We divide this exercise into standing and running jumps, and each of these can be subdivided into high and broad jumps.
In running contests, hurdles or other obstructions are placed in the path of the runner. These hurdles vary in height, but if you want to learn, start in with one or two about as high as your knee. Of course, you could take them standing, and it is not a bad exercise, but learn to take them at a moderate run. When you can do this with ease, increase the number or the closeness of the hurdles and add to the length of the run.
After a time you can take more and higher hurdles and lengthen the run, but never do either if you find your heart beating, or that the effort brings fatigue.
I do not think the running high jump pays for the effort. It is spectacular, that is all; not so the running broad jump. This may be of use. It is safe and sane, and with practice it is surprising the distance that can be covered.