284 



METABOLISM DURING WALKING. 



CHANGES IN PULMONARY VENTILATION. 



The data for the pulmonary ventilation (uncorrected for tempera- 

 ture changes) are also included in table 81, and are measured from the 

 kymograph curves in the same time-lengths as the respiration-rate, 

 i. e., full minutes for the standing position and 12 seconds and 15 sec- 

 onds for the walking. When the subject changed from standing to 

 walking, the measured values indicate that the ventilation doubled 

 within the first 12 seconds and continued to increase throughout the 

 first and into the second minute. By the close of the second minute 

 this increase appeared to diminish in several of the periods, but, as a 

 rule, it continued into the third minute. Beyond the third minute, 

 though increases occasionally appear in the values, they were not per- 

 sistent, and are without uniformity in direction. The values in the 

 fifth minute are seldom larger or even as large as those found in some 

 of the earlier minutes. While the figures show wide variations, the 

 general picture which they convey is that the immediate effect of the 

 work upon the ventilation was compensated for by the end of the 

 third, or possibly the beginning of the fourth minute, and probably the 

 ventilation reached approximate constancy by the time the subject 

 had maintained a uniform rate of walking for 4 minutes. The ventila- 

 tion during the periods on March 9 had a decided rhythmic effect 

 which makes it uncertain whether or not on this day the effect of the 

 work on the ventilation was offset by the third minute. This rhythm, 

 however, is not apparent on any of the other days. 



CHANGES IN RATE OF OXYGEN CONSUMPTION (UNREDUCED). 



The changes in the rate of the oxygen consumption (unreduced) as 

 the subject passed from standing to walking are shown in table 82. 

 These include data for both standing and walking on March 9, 14, 

 15, 16, and 17, 1916. A few values obtained on February 24 are also 

 given. 



TABLE 82. Rate of oxygen consumption of E. D. B. in periods of transition from standing to 



grade walking. 



