266 



METABOLISM DURING WALKING. 



10 C 



12 



co 



B 



A 



conditions (pp. 297 to 305). As in similar figures, the number 1 in- 

 dicates that the subject was sitting, and 2 that he was standing. The 

 time at which the subject began walking is indicated by the figure 3. 1 

 The points indicated by open circles represent per minute values ob- 

 tained in the interval between the experimental periods. 



Curve A in figure 30 gives a picture of the rate when the subject was 

 walking on a level up to 10 h 33 m a. m., stood until 10 h 40 m a. m., and 



thereafter walked on a 5 per 

 cent grade until 12 h 27 m p. m., 

 when he again stood for a short 

 tune. The course of the curve 

 is but little altered by the 

 change to grade walking, and 

 there were no sudden or marked 

 variations in the rate during the 

 forenoon. Curve B in figure 30 

 is also for an experiment with a 

 5 per cent grade preceded by 

 walking on a level, but on this 

 day the speed was a little 

 higher. Curve B has the same 

 general appearance as curve A, 

 however, except that the rise 

 due to the walking is somewhat 

 more marked. Both curves in- 

 dicate a slight fall at the begin- 

 ing of the walking on a level and 

 the usual fall in the pulse-rate 

 when the grade walking ceased 

 at the end of the experiment. 

 In curve A the pulse-rate after 

 the walking ceased reached 

 more nearly the initial level 

 than in curve B, but as the 

 observations were continued 

 only 7 minutes after the walk- 

 ing ceased, no information could 

 be gained as to how long a period elapsed before the pulse returned 

 to normal. In the curves in figures 31 and 32, showing the rate 

 after severe exercise, the pulse was still above the normal after 5 



l lt should be noted that the arrow indicates the time of the change and not the pulse-rate. For 

 instance, in fig. 31, curve A makes direct connection between the two readings at 9 h 31 m and 

 9 h 43 m a. m. ; the walking began at 9 h 42 m a. m. If the arrow were taken to indicate the pulse- 

 rate at this time, the rate would appear to be 142. On the contrary, it was probably more nearly 

 66 to 68, and the curve for the rise due to the activity of walking is actually much steeper than 

 here drawn. 



180 



160 



140 



120 



10C 



80 



GO 



-30p.ct._ 

 68melers 



3-* 



10 



\ 



11' 



FIQ. 31. Typical pulse curves of E. D. B., 

 with subject standing and walking on an 

 incline. (Values per minute.) 



2, subject standing; 3, walking on an incline. 

 Black points, records during experimental 

 periods; open circles, records between 

 periods. Curve A, Feb. 12; B, Feb. 14, 

 1916. 



