58 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



crude though it may be, the pedometer was used. Furthermore, the 

 men were frequently questioned as to their extraneous physical activ- 

 ities other than normal. During certain periods a schedule of the 

 actual activities during a period of one week was obtained. 



Pulse measurements. — The pulse is the best general index of the 

 metabolic level; hence every effort was made to secure pulse measure- 

 ments as frequently as possible, but under controlled and comparable 

 conditions. These included observations with the subject lying quietly 

 in the post-absorptive condition, sitting during meals, standing and in 

 the post-absorptive condition, lying quietly before and after riding on 

 a bicycle ergometer, standing before and after walking experiments, 

 and during walking. Wrist counts were supplemented by standard 

 electrocardiograms and electrocardiograms during exertion. 



Clinical examinations. — Clinical examinations of Squad A and of 

 Squad B during diet restriction were carefully made by Dr. Goodall. 

 These included examinations of the heart, lungs, reflexes, glands, and 

 blood pressure. 



Blood examination. — Somewhat late in the test arrangements were 

 made, through the kindness of Dr. George R. Minot of Boston, for a 

 series of careful blood examinations. We were so fortunate as to 

 secure the cooperation of Miss Anna L. Gibson and her associate. Miss 

 M. B. Conover, who made the blood examinations on nearly every 

 visit of the squads to Boston after December 19. 



Body temperature. — Each morning prior to the gaseous metabolism 

 experiments in Springfield, the temperature was taken in the mouth 

 with a clinical thermometer, simply to show the absence of fever. For 

 true physiological measurements we relied upon the temperature taken 

 in the rectum at the end of the night experiments in the large chamber 

 in Boston. To give a possible suggestion as to changes in skin tem- 

 perature, electrical measurements of surface temperature were taken 

 during the latter part of the test. 



Gaseous metabolism. — The gaseous metabolism was measured under 

 four different conditions: (1) With the subjects lying quietly and in the 

 post-absorptive condition, by means of the respiratory-valve apparatus 

 and the portable respiration apparatus; (2) with the subjects lying 

 asleep after a light supper, in a night experiment with the group respira- 

 tion chamber; (3) with the subjects in the post-absorptive condition 

 and in the standing position; and (4) with the subject walking on the 

 treadmill in the treadmill chamber. The first two measurements gave 

 an indication of the basal metabolism of the subjects, the third pro- 

 vided a base line for the metabolism during walking, and the fourth 

 supplied evidence of the energy requirements for the ordinary activ- 

 ities of the day. The fourth series of observations also gave informa- 

 tion as to the effect of a reduced diet upon the efficiency of the men in 

 ordinary physical activity. 



