30 Fisher — 7^7/6 Effect of Diet on Endurance. 



The t:il)k' .shows enormous differences in the figures even of the 

 same man for the same period. Tlius, the June improvement of 

 \V. reads 165 +, 20 4- , 77, 17o, 11 5 ±, 100 + . Such wide differences 

 between the improvements in different tests seem puzzling at first, 

 but they are explained, partly if not wholly, by two reasons. The 

 first is the obvious one that many of the figures are not exact records, 

 but understatements, and naturally their margin within the truth 

 will vary widely. Thus, the records for deep knee-bending (2) for 

 W. show merely that the improvement is ooer 26^c ; the true figure 

 may well be 100^, which would be more consistent with the other 

 figures. But the deep knee-bending test had been found in January 

 very painful and inconvenient in its after-effects, and there was there- 

 fore less inclination in the June tests to approach closely to the limit 

 in this particular test. 



The other reason is that in some tests a larger fraction of the total 

 strength of the muscle tested was called into play than in others. 

 Thus, "leg raising" requires a very large fraction of the strength of 

 the abdominal muscles, while "rising on toes" requires only a small 

 fraction of the strength of the calf muscles. This may explain why, 

 in general, the improvement in the test of the calf muscles seemed 

 so much greater than in that of the abdominal muscles. This expla- 

 nation is, however, purely hypothetical. It would be interesting to 

 find out experimentall}^ how much an improvement in the endurance 

 of a muscle shows itself when it is exerted in different degrees, sa}' to 

 Ibfc, oOfi and 25^ of its strength-capacity.' 



Bearing in mind these two possible reasons for the variations in the 

 figures, and also the fact that there must have been more or less actual 

 differences in the improvement of different muscles, we need not be 

 surprised at the disparities which the table shows. 



If we omit the cases in which the records are at all doubtful (with 

 suffix ±) or exaggerated (suffix — ), we have left the following table 

 for the eight men who showed improvement : 



remembrance of his January test. The " — " has been inserted whenever there 

 was the slightest groimd of any kind for thinking the figures might be overstate- 

 ments. With these figures weeded out, the remaining ones certainly understate 

 the actual improvement. 



' The original object of using the graded dnmb-bells, oO-lb., 25-lb., 10-lb., 

 and 5-lb. , for testing the biceps, was to throw light on this problem ; bnt for 

 reasons previously stated, these tests were not fully carried ont. 



