Fisher — The Effect of Diet on Endurance. 39 



to aid in this result. On the contrary, so far as the operation of 

 other factors was concerned, these must have worked against ratlier 

 than for the results achieved. Exercise was in no case indulged in 

 to a greater extent than had previously been the custom, and in most 

 cases it Avas less. The men were warned not to take up exei'cise, 

 except so far as they had been accustomed to befoi'e the experiment 

 began, and if they varied their exercise at all, to lessen rather than 

 increase it. They were very conscientious on this point, as on others, 

 — so much so that some of them at first gave up exercising until they 

 began to feel "logy." This over-zeal was corrected ; but in no case, 

 have I reason to think that the exercise taken was more, or more sys- 

 tematic, than previously. M. was probably the most systematic in 

 taking exercise. His statement on this point, as previously given, 

 the reader may care to review. / 



The men did not practice on the endurance tests between times. 

 This was expressly forbidden, and the men were too trustworthy to 

 admit of a doubt on this point. The tests themselves, needless to 

 say, were too far apart to have given any chance for repetition to 

 give " knack," and were too severe to count as beneficial exercise. 



Nor were the men more regular in their hours of retiring or other 

 habits. On the contrary, they were rather more reckless in burning 

 the midnight oil. It developed that, with their increased freedom 

 from fatigue, they indulged more freely than ever their propensity 

 to Avork in the lines of their respective ambitions. At first they felt 

 justified in doing this, as it accorded with their instructions not to 

 remove any handicaps to their chance of improving their endurance, 

 but to increase rather than decrease such handicaps. But this liberty 

 became license, and I was forced to remonstrate with the men for 

 their late hours and overstud}^, which tended to rob them of their 

 surplus endurance almost as fast as it accrued. Long before the 

 experiment was finished the men had given every appearance of 

 improved working power, but I was not at all sure that they would 

 have any of it left to show in the final test, because of their tendency 

 to use it up in work. Had the extent of their working proclivities 

 been realized in advance, it is doubtful if the experiment would have 

 been undertaken at all. It should be stated that all except M. were 

 graduate students, and almost all of them, in addition to their uni- 

 versity work, were earning their own way. 



The advance of warm weather must have tended, had not their 

 diet counteracted it, to tire the men, if, at least, Ave may trust com- 

 mon impressions as to " spring lassitude," 



