440 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



differences in the extremes are practically alike for the three groups, 

 but no striking relationship is apparent on the percentage basis. 



A comparison of the changes between the average standing pulse- 

 cycle duration preliminary to walking and that of the average dura- 

 tion of the first crest after walking began shows for the 5 normals a 

 change of 0.07 second, for Squad B 0.29 second, and for Squad A 0.24 

 second, or a percentage change from the standing pulse-cycle duration 

 of 10 per cent for the 5 normals and 25 and 23 per cent for Squads B 

 and A, respectively. 



A comparison between the changes in the duration of the pulse cycle 

 for standing and the durations that would correspond to the pulse- 

 rate found after 6 and 24 minutes of walking shows the normals had 

 the least tendency to a shorter duration. 



The curves of all three groups show that the pulse cycle lengthened 

 after the first reaction to the stimulus of walking. This change to a 

 lengthening cycle occurred between the fifth and tenth cycles, as a 

 rule, both with the normals and with Squads A and B. The length- 

 ening of the cycles continued to about the twentieth beat, when again 

 a shortened duration appeared which usually was persistent, and the 

 cycle did not again return to the duration shown at approximately the 

 twentieth beat. 



Recognizing the facts that the data here available are incomplete and 

 that we are dealing with an organ extremely sensitive to the mental 

 and physical conditions of the subject, which thus makes conclusions 

 upon its normal behavior difficult, we may say that there appears to 

 be no decrease in the promptness with which the heart responds to 

 the stimulus of walking, and the other characteristics of the pulse 

 aside from rate have not been fundamentally changed by the restricted 

 diet. From the foregoing it is seen that (1) the average percentage 

 variation for Squad A is greater than that for Squad B ; (2) that of the 

 three groups the 5 men with normal diet showed the smallest variation 

 in the pulse-cycle duration in the changes from standing to walking and 

 from walking to standing, and likewise the least variations in the 

 maximum and minimum durations during the first 60 seconds of walk- 

 ing; (3) that these men showed less change than the men with low diet 

 between the preliminary standing pulse-cycle duration and the dura- 

 tion which would correspond to the rates found after walking 6 and 24 

 minutes. These facts would seem to indicate a greater sensitivity of 

 the heart to demands upon the circulatory system when the body was 

 existing on a restricted diet. 



INFLUENCE UPON PULSE-RATE OF WALKING ON A TREADMILL. 



In connection with the walking experiments of January 6 and 28 

 and February 3, it was planned to secure the pulse records photo- 

 graphically with the subject sitting and standing preliminary to 

 walking, at the first, sixth, twelfth, and twenty-fourth minutes of 



