It was to ascertain the relation between diet and endurance in the light of the new knowledge shed upon the subject by Professor Chittenden’s experiments, that Professor Irving Fisher inaugurated his own experiments at Yale University. He conducted two series of tests, as follows:
First, to ascertain the effect of thorough mastication on endurance, following the rules laid down by Horace Fletcher, with the help of nine healthy students.
Second, to ascertain the influence of flesh eating on endurance as compared with the effect of abstinence from flesh, with a group of forty-nine persons, splitting the group as follows,—first, athletes accustomed to a flesh, or high proteid dietary; second, athletes accustomed to a low proteid, or non-flesh dietary; third, sedentary persons accustomed to a low proteid, or non-flesh dietary.
Prof. Irving Fisher, Ph.D.,
Professor of Economics at Yale University. His investigations have had to do largely with the cost of necessary food.
The flesh-eaters were Yale men, including some of the best known athletes of the university. The abstainers were nurses and physicians attached to the Battle Creek Sanitarium.
Professor Fisher’s interest in the subject was that of a political economist. Meats, as a general rule, are the most expensive part of the national diet, and it is apparent that if a fleshless, or low proteid, diet will increase endurance, it will also increase the national earning capacity, and thus add to the national wealth. When Professor Fisher began his experiments he encountered a singular fact, which was that the science of physiology had given very little attention to the study of endurance. “That strength and endurance are not identical, is only partly recognized,” he writes. “The strength of the muscle is measured by the utmost force that it can exert once; its endurance, by the number of times it can repeat any exertion within its strength. The repetition of such exertion, if not stopped by the refusal of the will, is finally stopped by the reduction of the strength of the muscle till it is unable to perform further. Thus endurance may be expressed in terms of loss of strength. It is related to fatigue, and it is only through the study of fatigue and fatigue poisons, made by Mosso and others, that light has been thrown on the nature of endurance.”
When these tests were held Professor Fisher had not then invented the machine for registering endurance which is now in use in the Yale gymnasium; therefore, three simple tests were employed: first, holding the arms horizontal as long as possible; second, deep knee bending; third, leg raising with the subject lying on his back.