EXPERIMENTS WITH HORIZONTAL WALKING. 



163 



E. D. B. in table 45. The average percentage changes in the ventila- 

 tion for all of the subjects, as calculated for approximately the same 

 speed, i. e., 52.6 to 63.2 meters per minute, are likewise given in 

 table 45. It is apparent from these percentages that the differences 

 between the individual subjects are very great. Even if we exclude 

 those subjects for whom we have the least data and compare the results 

 for W. K. and E. D. B., with whom the greatest number of experiments 

 were made, we still find a r^nge of from 59 to 7 1 per cent for practically 

 the same speed of walking. 



The effect of the increase in speed upon the ventilation for the indi- 

 vidual subjects can be seen from the group averages in table 44. 

 H. R. R. shows an increase, T. H. H. shows no change, while with 

 W. K. there was a slight increase. With E. D. B. there was practically 

 no change for the three lower speeds; for the speeds between 56.5 and 

 72.2 meters per minute there was an increase over the preceding groups, 

 but within this range the ventilation was quite constant, while above 

 this speed the rate of increase was much greater. This is seen in table 

 45, in which the increase in the ventilation over the standing is figured 

 percentagewise for this subject for the various speed-groups given in 

 table 44. The slight difference in the percentage for the moderate 

 speeds with the marked increase for speeds above 77.5 meters is here 

 very apparent. 



TABLE 45. Percentage increase in pulmonary ventilation over standing requirement with 

 E. D. B., at increasing speeds of horizontal walking, and for all subjects at approxi- 

 mately the same speed (53 to 63 meters). (Values per minute.) 



PULSE-RATE DURING HORIZONTAL WALKING. 



The belief that there is a relationship between the pulse-rate and 

 the degree of metabolism for the same subject has been expressed 

 in previous reports from this Laboratory, 1 and for a number of years 



Benedict and Cathcart, Carnegie Inst. Wash. Pub. No. 187, 1913, pp. 153 and 172; Benedict 

 and Murschhauser, Carnegie Inst. Wash. Pub. No. 231, 1915, p. 69; Harris and Benedict, Carnegie 

 Inst. Wash. Pub. No. 279, 1919, p. 79. 



