Why? The Science of Athletics

HUMAN MECHANISM I09 and is lined with the tiny glands which produce the gastric JUICes. The stomach, however, does not carry out all the work of digestion, and sugars, starches and fats are passed on, by the automatic action of a sphincter muscle, into the small intestine, where food is further absorbed and digested. While the digestive process is going on neither violent exercise nor brain work should be attempted, because the work the stomach is doing automatically draws blood from both brain and muscles for the time being. All the while t~e food is in the intestines, right on until there is nothing left but refuse when it reaches th~ lower end, peristaltic waves are stirring the food and moving it along, the movements being due to the working of involuntary muscles, partly automatically and partly by the action of the involuntary nervous system. In the small intestine all sorts of digestive processes go on, which it is not necessary to deal with in detail at the moment. Then the pulped and semi-digested food enters into and moves slowly along the bowel, and it is here that most of our nourishment is taken into the blood ; and if you consider how long it takes for food to pass through the body from the time it enters the mouth until the final refuse is excreted, all the nourishment having been absorbed meantime, you will see readily enough that it is the food eaten on the day before a contest, and not the meals taken on the day itself, which is the all important factor in obtaining the athlete's nourishment for the big event. There are, of course, other kinds of involuntary muscles, notably those that surround the blood vessels and regulate our blood pressure and those contractile involuntary muscles which create the particular skin condition popu– larly styled "goose-flesh" when we are cold. One impor– tant characteristic of involuntary muscles is that their action is slower and more economical than that of the voluntary muscles.