You should remember all through your life that each member of the body, in the very act of living, produces poison to itself. When this poison accumulates faster than it can be thrown off, which always occurs unless the muscle can have an interval of rest, then will come fatigue, which is only another expression for poisonous infection――real, genuine poison. If the muscle is given an interval of rest, so that the cell can give off its waste product to keep pace with the new productions, the muscle will then liberate energy for a long time. This latter condition is what we call endurance. When you say a boy has long endurance it simply means that all his organs are in perfect working order; that they repair as soon as they waste. Such a condition kept up means a long life and a healthy one. And you can all obtain this state, as I shall later on show you.
The power and endurance of the human machine are limited according to our understanding of the above facts. But another important bit of knowledge is necessary to have if we wish to avoid ruining our physical energy: that is, to recognize the necessity of starting the human machine slowly. Like any other ponderous and intricate machine, the body requires time to get in harmonious working order. What would you think of an engineer who started his engine off with a jump at high speed? What would happen to a big engine if the throttle were pulled wide open at the instant of starting?
The brain, nerves, heart and muscles must be given some warning of the work they are expected, collectively, to perform. Ignorance of this fact has broken down many a young man who aspired to honors on the cinder-path. The necessity of getting all the parts of the body slowly in working order is well understood by trainers and jockeys on the racetrack, as is evidenced by the preliminary “warming up” they give their horses, although it is doubtful if the trainers could give any physiologic reason for the custom.
I once asked an old darky trainer in the South why he always ran his horses just before a race, and he replied, “I’s got ter ile ’em up; jus’ ile ’em up.” Then he shouted to a little bow-legged coon on a big bay horse: “Youse, git a goin’ dar, Sam; git ’im iled up so I kaint heer ’im squeek――git de ile in ’is jints; go dar!” And Sam went on “iling ’im up.”