Although the pronounced influence of various forms of muscular activity upon the total metabolism and hence upon the total demands for food is so great, it was admitted at the outset that exact records of muscular activity of a group of 12 to 25 men, though desirable, were impossible. On the other hand, since it could not be assumed that all the men would have the same degree of muscular activity, we believed that we should nuke every effort to obtain a quantitative idea of relative, if not absolute, activity of the various members of Squad A. Records made with the pedometer gave a crude index which was of great assistance and not without quantitative value. All of the subjects were provided with pedometers, which were worn continuously and which were read once or twice each day and the results carefully recorded. Ideally each pedometer should have been set to accord with the uniform length of step for the individual subject, but it was not feasible.

1 Benedict, Am. Journ. Physiol., 1916, 41, p. 275.

2 Poee C gives a profile view (from the left) of the subject standing at " attention," with the left arm extended and the fingers separated. (See figs. 74 to 85, p. 240).

Many of the subjects were unusually interested in physical activities and some were specially proficient. Frequent reference is made in their personal histories to incidents calling for unusual muscular activity. Thus, some of our men ran in cross-country teams, others devoted considerable time to instructing gymnasium classes, swimming, tennis, football, hockey, or bicycle riding. Records were made of this unusual activity. Finally, one of the college instructors outlined in another connection a course in personal efficiency, which called for an exact cataloguing of each day's activities and approximated in a way a gross motion study. The personal records of the few of our squads who took the course are of special interest for comparison with other men who took the course but were not on diet, as they indicate to what extent the members of the reduced diet squads lived up to the physical and mental activities of their college mates. The men were urged not to curtail their college activities, either intellectual or physical, and while we could have absolutely no control in this matter, we believe that, in general, they did not try to save themselves. In several instances we are perfectly certain that activities were curtailed and in other cases, particularly during the period when extra efforts were made to reduce weight, the physical activity of some men greatly exceeded that usual for them and surpassed that of their fellow students. These personal records are therefore of unusual assistance as an indication of the validity of the comparison of the men on this squad with their confreres.

Clinical Examination

It was not sufficient to assume that our subjects were healthy young men or, as in earlier researches with normal individuals, "presumably in good health," but the changes possibly resulting from the reduced diet were considered of sufficient moment to be noted by an expert clinician in an ordinary routine clinical examination. It was our good fortune to enlist the interest of Dr. Harry W. Goodall, who made a careful and helpful study of the subject of the prolonged fasting experiment reported from this Laboratory in 1915.1 Dr. Goodall saw the men in Squad A at practically every visit to Boston, but unfortunately could not observe them prior to the commencement of the reduced ration. The men began the reduced diet on October 4, 1917; Dr. Goodall's first examination was on October 13, 1917. Squad B was likewise examined on January 5, prior to restriction in diet, and subsequently when living on the reduced diet. The examination was carried out according to the methods used by our foremost clinicians.

1 Benedict, Carnegie Inst. Wash. Pub. No. 203. 1915.

Blood Examination

Through the kindness of Dr. George R. Minot, we secured the assistance of Miss Anna L. Gibson, superintendent of the Huntington Memorial Hospital, Boston, and her associate, Miss Myra B. Conover, who made the routine blood examinations of the subjects in both squads from December 19, 1917, to the end of the observations. Here again this series of examinations was unfortunately not begun early enough to secure normal values on Squad A, although they were obtained on Squad B before and during the reduced diet period. Both the red and white blood counts were made with the Thoma-Zeiss counting chamber. The hemoglobin was determined with the Sahli hemometer. It is important to note that the instrument used in this research gave low values for normal blood, i. e., about 85 per cent.