142 METABOLISM DURING WALKING. 



the energy expenditure, though slightly above the average, was not in 

 any way exceptional. 



From these considerations it may be seen that the value of 0.478 

 gram-calorie, while representing an average figure for this subject for 

 the 61 days, does not show the energy cost for a trained subject. If 

 we take the values found for December and March, and thereby elimi- 

 nate the influence of the early data and also the extremely high and 

 low speeds of April, an average value for the energy cost is obtained 

 for E. D. B. of 0.446 gram-calorie. This is much lower than the aver- 

 age value of 0.55 gram-calorie reported by Benedict and Mursch- 

 hauser 1 in their summary of the work of earlier observers. But in 

 many cases these average values for the earlier observers include 

 experiments performed when the subjects were not in a strictly post- 

 absorptive condition and in a few instances require an assumption of 

 the respiratory quotient. Moreover, different techniques were em- 

 ployed in the various researches. There is, therefore, no reason to 

 believe that the value of 0.478 gram-calorie as an average for an un- 

 trained subject over a considerable period or of 0.446 gram-calorie for a 

 trained subject is exceptionally low. 



This effect of training finds support in the figures from the report of 

 Benedict and Murschhauser, 2 although the authors themselves do not 

 consider the evidence is sufficient to make any conclusion in the matter. 

 It is seen from their figures that their Subject I had a value of 0.507 

 gram-calorie as an average for 16 experiments made during a period 

 of 1 month. The average for the 4 last days of this period, however, 

 was 0.488 gram-calorie and for the first 5 days 0.515 gram-calorie. 

 Also, their Subject II in 57 experiments had an average cost per hori- 

 zontal kilogrammeter of 0.493 gram-calorie 3 but for the first 10 days 

 of his experiments the average value was 0.506 gram-calorie, while for 

 the last 6 days beginning with April 22, which was after 18 days of 

 walking, the average value was 0.481 gram-calorie. These latter 

 days, moreover, are when their subject was walking at a speed near the 

 point of maximal efficiency. 



It is to be regretted that there were no horizontal-walking experi- 

 ments with E. D. B. in the last part of December or the first part of 

 January, when the standing metabolism of this subject was found to 

 have risen to a higher level. (See p. 98.) But the fact that the energy 

 cost per horizontal kilogrammeter for the approximate speeds of 55 to 

 77 meters per minute was as a rule higher during March or April than 

 during the early part of December (see table 34) indicates that the 

 increase in the metabolism shown by his standing requirements was 

 also apparent in the cost per horizontal kilogrammeter. 



Benedict and Murschhauser, Carnegie Inst. Wash. Pub. No. 231, 1915, p. 28. 

 'Benedict and Murschhauser, Ibid., p. 79. 

 'Benedict and Murschhauser, Ibid., p. 87. 



