The pulse-rates thus far considered were all obtained with the subject lying in the morning before breakfast and represent the minimum basal values.1 In connection with the study of the return of the heart to normal after a definite amount of moderately vigorous physical exercise, Professor A. G. Johnson, of the faculty of the International Y. M. C. A. College at Springfield, determined the pulse-rates of the subjects in the lying position. His procedure in these experiments was as follows: After the subject came to the room containing the ergometer, he lay down on a table and the radial pulse was taken every minute until at least three successive observations gave the same rate. This usually required from 4 to 10 minutes. During this time the subject was required to lie quietly with muscles relaxed. He was then placed on the ergometer. After riding the man got off quickly and again lay down on the table, this change of position taking about 5 seconds. Subsequently the pulse was counted during the first 15 seconds of each minute until the rate became normal.

At present we are primarily interested in the pulse values recorded with the subject in the lying position prior to the work. The first observations under these conditions were obtained on October 19 and usually followed at 3 or 4 day intervals throughout the rest of the study, excluding the Christmas recess. In considering these pulse-rates it should be borne in mind that they were obtained after a relatively short period of relaxation. The ergometer was in a room on the second floor of the gymnasium. Frequently the subjects ran rather rapidly up the steps to this room, and it is conceivable that the time allowed for the pulse to reach normal, namely 4 to 10 minutes, was hardly long enough. On the other hand, as the increment due to riding was frequently over 100 per cent, the values were sufficiently exact as a base line for Professor Johnson's study.

These pulse values also differ from those previously discussed as the subjects were not in the post-absorptive condition. All observations were taken between the hours of 9h30m and llh30m a. m., and lh30B and 4h30m p. m., i. e., from 2 to 4 hours after the last meal. Under these conditions the pulse-rate was undoubtedly influenced to a certain extent by food ingestion which would tend to increase the values. Since each man usually came for his test at approximately the same hour of the day, the results are more or less comparable with one another.

1Some of the electrocardiograms, as previously noted, were not taken under these conditions.

Bro, Gul, and Gar of Squad A did the work on the ergometer between the hours of 9h30m and llh30m a. m. The rest of the men in Squad A came in the afternoon between lh45m and 4h30m o'clock, nearly always in the following order: Pec, Vea, Can, Moy, Spe, Mon, Tom, Kon, and Pea. In Squad B, How, Ham, Wil, and Liv always came between 9h30m and 11 a. m. The rest of Squad B came between the hours of 2 and 4h30m p. m., as follows: Sne, Van, Har, Tho, Lon, Fis, Sch and Kim.

Pulse-Rate, Lying Before Work, Squad A

The normal pulse-rates of the subjects in Squad A prior to the bicycle-ergometer experiments, as recorded by Professor Johnson, are given in table 84. Unfortunately these interesting values were not obtained during the normal diet period, as the records did not begin until October 19, when the men had already been upon a reduced diet for practically two weeks. The individual values show, however, a striking tendency toward a falling off in pulse-rate, although, as would be expected, relatively few reached 40 or below, hence the number of italicized figures showing this lower level is proportionately reduced and but few figures in bold-face type are to be noted. Emphasis must again be laid upon the fact that these pulse-rates were no doubt influenced by the presence of food in the stomach and previous moderate exercise.

These pulse-rates, however, are the best pulse records we have of the post-diet condition of the men in Squad A. The restricted diet was discontinued on February 3. Professor Johnson made a series of observations 5 days later (February 8), which are perfectly comparable with those made on January 31. All of the men who were available for observation on the later date showed pronounced rises. The greatest increase is that with Kon, whose pulse nearly doubled, rising from 45 to 82. The smallest rise was observed with Gar, the increase being from 58 to 66. The average rise for the entire squad was from 48 to 71. A still further average increase was noted on February 11, but constant values were obtained for the following 2 days. From February 20 to March 7, inclusive, there is a definite tendency for a slight falling oft* in pulse-rate from the higher level of February 11, 15, and 18, so that the average for the last 5 days of observation is not far from 68. The isolated instance of a pulse-rate of 89 obtained with Tom, which is included in the average, should be called to attention. Undoubtedly 89 is an aberrant figure which should not legitimately be included in the average, but it is used here, as it represents the absolute highest pulse-rate in the table.