EXPERIMENTS WITH HORIZONTAL WALKING. 



141 



though the change is not so great as with 55 meters per minute. The 

 experiments at the speed of 77 meters per minute were first made late 

 in October, and the effect of the training had already taken place to 

 some extent. Moreover, at this speed, the subject was approaching 



TABLE 34. Daily values for metabolism of E. D. B., grouped chronologically on the basis of 

 speed, to determine effect of training. (Values per minute.) 



1 After recess of 3 weeks. 



the point which Durig has termed "the maximal efficiency speed," 

 above which the energy cost increases in a faster ratio. In spite of 

 these neutralizing factors, there is evidence of a fall in the energy cost 

 between the end of October and the middle of November. The speed 

 of 45 meters per minute was not used until October 30, but even these 

 values indicate a decrease in the latter part of the series. It seems 

 clear, therefore, that in the early horizontal-walking experiments with 

 E. D. B., lack of practice or training was a factor in the energy require- 

 ment. In this connection it should be noted that on January 31, on 

 E. D. B.'s return from a three weeks' recess due to a lame foot, he had 

 a much higher energy cost per horizontal kilogrammeter than at the 

 end of his previous walking experiments. This may be an erratic 

 result, for it may also be noted that on the second day following 



