THE INFLUENCE OF DIET ON ENDURANCE 539
give marked evidences of over-exertion, although not in training. At the time these experiments were tried Mr. Fletcher weighed one hun- dred and fift3'-seven and a half pounds, and was in his fifty-fourth year. "\Miile, naturally, we have not been able to obtain daily records of the quantity of food taken by Mr. Fletcher during the past four years, observations made from time to time have confirmed his general state- ment that he lives essentially at this same low level of proteid metab- olism. In June, 1907, Mr. Fletcher was again at ISTew Haven for some weeks, thus giving us an opportunity to test his rate of nitrogen ex- change and his physical condition. It was found that the amount of nitrogenous or proteid food consumed daily never exceeded sixty grams, and that his nitrogen metabolism averaged not far from seven grams per day. His body-weight was found to be one hundred and seventy- seven and a half pounds. We thus had an opportunity of testing the physical endurance of a man who has for at least nine years practised a degree of physiological economy in nutrition, which means a daily consumption of proteid food in amount less than one half that called for by the ordinary dietary standards. It would seem reasonable to suppose that if a low nitrogen intake is destined eventually to prove detrimental to the individual, some sign of such deleterious effect would manifest itself during this period of time. If, on the other hand, consumption of proteid food in harmony with the lower dietary standards which the writer is disposed to advocate on the basis of his experimental results, is beneficial to the individual, then one might expect to find a continuance of the same physical vigor noted in the earlier observations on Mr. Fletcher, in spite of the fact that at this date the subject was nearly fiftA'-nine years of age.
Through the kindness of Dr. Anderson, of the Yale Gymnasium, Mr. Fletcher was subjected to a variety of tests, the outcome of which is best presented in the words of Dr. Anderson, as given to the writer in a report made under date of June 28, 1907.
On June 11, 1907, Mr. Fletcher again visited the Yale Gymnasium and undenvent a test on Professor Fisher's dynamometer. This device is made to test the endurance of the calf muscles. (Soleus and gastrocnemius.) The sub- ject makes a dead lift of a prescribed weight as many times as possible. In order to select a definite weight the subject first ascertains his strength on the Kellogg mercurial dynamometer by one strong, steady contraction of the muscles named — and then he finds his endurance by lifting three fourths of this weight on the Fisher dynamometer as many times as possible at two- or three-second internals. One leg only is used in the lift, and, as indicated, the right is usu- ally chosen.
Mr. Fletcher's actual strength as indicated on the Kellogg machine was not quite 400 pounds, ascertained by three trials. In his endurance test on the Fisher machine he raised 300 pounds 3.50 times and then did not reach the limit of his power. Previous to this time Dr. Frank Born, the medical assistant at the gymnasium, had collected data from 18 Yale students, most of whom were trained athletes or gymnasts. The average record of these men was 87.4 lifts, the extremes being 33 and 175 lifts.
It will be noticed that Mr. Fletcher doubled the best record made previous to his feat and numerous subsequent tests have failed to increase the average