In obtaining the basal values for a series of treadmill experiments at the Nutrition Laboratory, individual measurements were made with the men in both squads standing prior to walking, i. e., on the mornings of January 6 and 28 with Squad B and on the morning of February 3 with Squad A. With Squad B the values determined on the morning of January 6 were prior to the diet restriction; those found on the morning of January 28 were after 3 weeks of low diet. With Squad A the measurements were made on the last morning of the experiment. This experimental material, while collected in a somewhat unsatisfactory manner, since only one experiment of two periods was made with the portable respiration apparatus for each subject, supplies interesting evidence regarding two important points. The data regarding the basal metabolism were measured in these standing experiments under exactly the same experimental conditions as the minimum values obtained with the group respiration chamber in that they were secured with the subject in the post-absorptive condition and without muscular activity, other than that required for standing, and, with Squad B, both before and after diet restriction. On the other hand, the values for the standing position would be expected to be distinctly higher than those measured with the group respiration chamber, since in the latter apparatus the subjects were lying in deep sleep.

Gaseous Metabolism With Standing Position. Squad B

With Squad B a comparison may be made of the values obtained with the subject in the standing position before and after diet reduction; such a comparison is made in table 136. These values give us not only the average value for the whole squad, but likewise enable us to study the changes in the metabolism of individual members of the squad. Since the heat production per minute is used in subsequent tables for the calculation of the metabolism during the treadmill experiments, it is retained in table 136, but the values of special interest to us in this discussion are those computed for the heat production per kilogram per hour for January 6 and for January 28. The decrease in the heat production on this basis as a result of the reduction in diet, also the percentage of decrease, are recorded in the last two columns of the table, the data obtained on January 6, with normal diet, being used as the basal values. As the personnel of the squad changed somewhat between these two dates, and How found difficulty in breathing through the mouthpiece of the apparatus (see page 535), the values for only 10 men are available for comparison.

From the data in table 136 we find that after 3 weeks of low diet each man in Squad B showed a decrease in the heat output per kilogram per hour which ranged from a minimum of 0.11 calorie with Sne to a maximum of 0.29 calorie with Tho, with an average of 0.17 calorie for the whole squad. On the percentage basis these 10 men showed on the average a decrease of 14.1 per cent, the minimum being 9.5 per cent with Site and the maximum 22.1 per cent with Tho. The percentage decrease for practically all of the other men was not far from the average of 14.1 per cent. We may conclude, therefore, from these two series of experiments that a lowering of the metabolism per kilo-gram due to the restriction in diet is shown not only when Squad B was measured as a group, but when the men were measured individually. In the discussion of table 134 (see p. 523) it was brought out that when the values for January 6 were used as a base-line the low diet produced a decrease in the metabolism of the group as a whole of 13.3 per cent with the subjects lying quietly asleep in the group chamber. This value is almost identical with the reduction shown in table 136 of 14.1 per cent for 10 members of the squad standing quietly. This fact has a double interest, first, as a general confirmation of the lowering of the metabolism due to the decrease in the amount of food, and second, as an indication that with a low diet not only is the heat output during complete muscular repose reduced about 13 or 14 per cent, but likewise the heat output with the subject standing with a slightly higher metabolic level shows a similar percentage reduction.

Table 136. - Post-Absorptive Metabolism During Standing Preliminary To Walking On Treadmill - Squad B

The metabolism for the standing and lying positions can not be compared with each man in Squad B to note the effect of change in position, as no individual measurements of the metabolism were made with these subjects in the lying position, and comparisons with other individuals in the lying position would have no significance in this connection. A group comparison can be made, however. If we compare the values found in table 134 with those given in table 136, we find that the basal metabolism with the subjects lying quietly on the night of January 6 was, for Squad B, 0.98 calorie per kilogram per hour. The average value for the standing position as determined with the portable respiration apparatus on the morning of January 6 was 1.22 calories per kilogram per hour, an increment of approximately 24 per cent of standing over lying in complete muscular repose. The basal value found with the whole group on January 28 when the subjects were lying quietly in the large respiration chamber was 0.85 calorie. To compare with this we have the average value of 1.04 calorie on the morning of January 28. Under these conditions the increase in metabolism due to standing may be taken as 22 per cent. Thus, although there has been an actual decrease in the metabolism as a result of the restriction in diet, not only with the subjects asleep and quiet, but likewise when they were standing and quiet, the influence of the standing upon the basal metabolism is practically identical under the contrasting conditions of diet, namely, an increase in the heat production per kilogram of body-weight due to standing of 22 to 24 per cent.