296 METABOLISM DURING WALKING. 



sumption during standing were also made on January 1, February 14 

 and 17, 1916. These results are likewise included in table 85, and 

 show that during the first minute of standing after walking ceased there 

 was a contraction in the oxygen consumption ranging from 600 to 

 1,400 c. c. between the second and the fourth or fifth fractions of the 

 first minute. No measurements were made for the first one-fifth min- 

 ute of standing on account of irregularities in the record, and no 

 measurements of the oxygen consumption during walking on these 

 dates are available for the transition period. Any real comparison 

 must therefore be confined to the two days for which we have more 

 nearly complete data. 



The results for March 10 and 11, 1916, include both walking and 

 standing values for four periods on each day. The first point which 

 attracts attention is the fact that the oxygen consumption during the 

 first two one-fifth minute measurements for standing usually indicates 

 an increase over the walking rate. The tracings in this portion of the 

 transition record were always irregular at their low points, implying 

 that the transition disturbed the normal type of respiration. It is thus 

 difficult to determine the course of the rise in these few seconds, since 

 an error of 2 mm. represents approximately 80 c. c., and a few disturbed 

 respirations at this point could easily introduce an error of double this 

 amount in the probable course. This disturbance presumably rep- 

 resented a temporary alteration in the residual air in the lungs. It is 

 only after these first disturbances have passed that the true change 

 taking place in the oxygen consumption is apparent. This point was 

 reached by the third or fourth one-fifth minute, when the fall amounted 

 to approximately 400 or 500 c. c. By the end of the first minute the 

 oxygen consumption had fallen to approximately one-half of the values 

 found with the subject walking. The drop from this point is almost 

 uniformly progressive during the second minute and continues with 

 somewhat less regularity to the end of the measurement. If, from the 

 data in table 82, the normal unreduced oxygen consumption of E. D. B. 

 for the standing position be taken as 280 c. c. per minute, it is seen 

 that in only two cases is there an approach to this figure by the end of 

 the measurement (see March 10, period 1, and March 11, period 3); 

 that is, during the time that these measurements were extended (5 or 

 6 minutes), the oxygen consumption continued above the normal stand- 

 ing requirements. It is also seen that, after the first unreliable readings 

 due to a disturbed record, the fall was approximately uniform. 



CONCLUSIONS REGARDING RESPIRATORY CHANGES IN TRANSITION FROM GRADE WALKING 



TO STANDING AND THE REVERSE. 



From these measurements it is thus found that during the period of 

 transition from standing to walking, the respiration-rate responded 

 within 12 seconds and the maximum change was over by the end of the 

 first minute; that the pulmonary ventilation responded within the 

 first 12 seconds to double the standing value, and continued increasing 

 through the third minute, while the oxygen consumption increased 



