304 



METABOLISM DURING WALKING. 



lengthening of but 0.02 to 0.03 second. In the next 50 cycles there 

 was a further fall in the curve to 0.42 second, and by the end of 150 

 cycles the duration was between 0.45 and 0.46 second, or a lengthening 

 of the cycle of but little more than 0.1 second. This is in decided con- 

 trast to the rapid rate of change shown in the transition from standing 

 to walking, when most of the change occurred within 100 cycles. 

 The 150 cycles of curve A occupied approximately 1 minute, and the 

 following minute brought the duration to but 0.49 second. The return 

 of the cycle duration during the first few minutes of standing is there- 

 fore slow in comparison to the transition in the change from standing to 

 walking. 



0.30 

 .32 

 .34 

 .36 

 .38 



UJ 



r! -40 



3 



.46 



O 

 K.48 



o: 



a so 



200 100 100 200 300 200 100 100 200 300 100 O 

 PULSE CYCLES 



100 2OO 300 



FIG. 42. Duration of pulse-cycles of E. D. B. in transition from grade walking to stand- 

 ing, as indicated by average cycle duration for measured groups of 10 pulse-cycles. 



Beginning of standing at Y. A, Feb. 12; B, Feb. 14; C, Feb. 17; D, Feb. 15. The time 

 required for groups of cycles, varying in number, is indicated by small figures and 

 inclusion marks at the bottom of each chart. 



The behavior of the pulse-cycle in curve B is almost the same as that 

 found in curve A. The duration just previous to the transition is 

 practically the same. At the end of 100 cycles the duration has 

 lengthened to 0.42 second, or but 0.08 second. At 150 cycles, occupy- 

 ing approximately 60 seconds, the duration was about 0.46 second. 

 Two minutes of standing resulted in a total lowering of the duration of 

 the pulse-cycle 0.12 second. This curve shows some lag at the transi- 

 tion which other curves do not show. 



In curve C the duration of the pulse-cycle lengthened from 0.33 

 second preceding the transition to standing to 0.37 second in 50 cycles, 

 \ ^jle in 150 cycles after the walking ended, occupying approximately 

 i 3conds, the duration lengthened to 0.44 second, or a total lengthen- 

 ing of 0.11 second. This rate of lengthening agrees with that found 

 in the two preceding curves, namely, in 150 cycles of approximately 

 60 seconds of elapsed time, the change in the average duration of the 

 cycle was but little over 0.1 second, and by the end of 2 minutes the 



