The important relationship between muscular work and total metabolism made it incumbent upon us to obtain all possible information with regard to the relative physical activities of these groups of men and their college mates. The diet was to be reduced by design. If the physical activity were likewise considerably reduced, it is obvious that the diet might still be a maintenance diet without a material alteration in the general condition of the body. While the main criterion was to be a reduction in weight of 10 per cent, which would inevitably take place if the supply were materially less than the demand, it still would definitely disturb the relations of the experiment if the subjects reduced the physical activity appreciably. The men were repeatedly instructed and, indeed, urged to keep their bodily activities as nearly normal as possible. It was impressed upon them that the aim of the experiment was to study the effect of a reduced diet upon the efficiency of a group of men in carrying out the ordinary activities of the collegiate life. If they voluntarily and deliberately reduced these activities at the beginning they would not be fulfilling the prime condition of the experiment and would seriously vitiate the results.

These men were all college students and had the regular college program to carry out. This involved a certain amount of walking to and from classes in the different buildings and to the main dining-hall for the several meals, also the gymnasium work prescribed in certain college courses. Furthermore, as with most college students, walking was a regular form of exercise and recreation outside of the prescribed college work.

One development we did not anticipate was the fact that in many instances the men made special efforts to reduce the weight at the beginning of the experiment. To hasten the loss of fat and thus reach the 10 per cent level quickly, they indulged in unusually strenuous and prolonged exercise. The subjects reasoned that the sooner the desired weight reduction was attained, the sooner they would receive larger amounts of food to hold them at this level. This same increase in physical activity appeared several times throughout the course of the experiment, particularly after the uncontrolled Sundays, the short Thanksgiving recess, and the Christmas vacation.

Two attempts were made to secure quantitative estimates of the daily physical activity of these men. It was believed that at least a rough estimation could be obtained by means of pedometer records. Accordingly, each man was supplied with a pedometer which he wore continuously, and daily readings were recorded. When used for level walking over reasonably smooth roads, and particularly when a measure of the length of step has been obtained in walking over a measured distance, the pedometer gives a very satisfactory record of distance walked. It was recognized at the outset, however, that in using these pedometers these men must record activities other than the simple up-and-down motion of the body incidental to ordinary level walking. Accordingly our pedometer records should be looked upon primarily, not as the summation effect of so many up-and-down motions of the body, but as the summation of a large number of body-motions differing materially at times in intensity, and thereby in energy requirements.

Table 191. - Daily Record Of Walking (Pedometer) Of Vea During Period Of Reduced Diet

1Thanksgiving recess, Nov. 29 to Dec. 2. inclusive; diet uncontrolled during this period. 2Christmas recess, Deo 20 to Jan. 6, inclusive; diet uncontrolled during this period. 3Vea ill Dec. 23-24.

The pedometers used were all of the same make and were set at the uniform step of 27 inches employed in the factory setting; no attempt was made to adapt the setting to the individual. The pedometer records for the entire group of men are reasonably complete. It is obviously impracticable to report the pedometer readings for the individual men for each day of the entire experiment, hence in table 191 we give only a typical set of records for one subject, Vea, to illustrate the general method of recording.

Here again the need of normal data is apparent, for unfortunately the pedometers were not given to the men in Squad A until after the reduction in diet took place. For these men, therefore, it will be necessary to use normal data subsequently secured with Squad B and other volunteer members of the undergraduate body of the college for comparison with the values obtained during the low diet.

A general examination of table 191 shows that, excluding the Thanksgiving and Christmas recesses, Vea walked daily on the average, in October 6.3 miles, in November 6.0 miles, in December 5.9 miles, and in January 5.6 miles. During the Thanksgiving and Christmas recesses, there was a great increase in the miles walked per day, the distance walked amounting on December 31 to January 1 to 301 miles. The general picture of this pedometer record shows that Vea did not alter his activity materially as the experiment progressed and the low diet continued.