370 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



BLOOD PRESSURE. 



As the blood pressure is an important fiactor such determinations 

 were made a part of the regular clinical examinations by Dr. H. W. 

 Goodall when the men came to Boston for the experiments in the 

 group respiration chamber. Standard technique was used, namely, 

 the apparatus of the Taylor Instrument Company (Tycos) and the 

 auscultatory method for both systolic and diastolic pressures. The 

 particular instrument employed had the usual Bourdon gage. This 

 was frequently compared with a mercury manometer to insure the 

 accuracy of the blood-pressure records. The blood pressures recorded 

 by Dr. Goodall were always taken with the subject in the sitting 

 position and with the cuff on the left arm. These determinations 

 were almost invariably made between 8 and 10 p. m., before the 

 subjects entered the respiration chamber. 



In the latter part of the research, a series of blood-pressure tests 

 was made with a second instrument by one of us and by the skilled 

 superintendent of the Huntington Memorial Hospital, Miss Anna L. 

 Gibson. This instrument (a duplicate of the one used by Dr. Goodall) 

 was likewise compared with a mercury manometer and its accuracy 

 established. We have every confidence, therefore, in the two instru- 

 ments used. Special emphasis is laid upon this fact, for the astounding 

 changes in blood pressure render the technique liable to special 

 scrutiny. 



The second series of blood-pressure observations included a consider- 

 able number of blood pressures which were taken prior to the walking 

 experiments. Successive observations were also recorded immediately 

 after the cessation of walking. The subject was always in the stand- 

 ing position during these determinations, for the first few records, but 

 additional records were made with the subject sitting, usually from 5 

 to 9 minutes after the walking had ceased. The series of observations 

 after walking provided data for studying the influence of a moderate 

 amount of physical work upon the blood pressure, both systolic and 

 diastolic, and likewise upon the pulse pressure. Such records were 

 deemed significant inasmuch as Cotton, Rapport, and Lewis^ found 

 a pronounced influence upon blood pressure with strenuous muscular 

 work, even when continued only a short time. 



Of special interest in this study is the course of the systolic and 

 diastolic blood pressures and the pulse pressure as the investigation 

 progressed. Unfortunately, we were not able to obtain records of 

 blood pressure for Squad A prior to dietetic restriction. The need 

 of such data is specially brought out in examining the blood pressures 

 of the 12 members of Squad B. With Squad A the blood pressure was 



^ Cotton, Rapport, and Lewis, Heart, 1917, 6, p. 269. 



