Standing Pulse Records In Experiments With Portable Respiration Apparatus

Any records of pulse-rate taken under uniform conditions in a given position are of value as evidence of the influence of reduced diet upon this factor. A number of respiration experiments were made with these men which were designed primarily to determine the basal metabolism with the subject in the standing position prior to a series of measurements of the energy transformations during walking. This led to the recording of a number of pulse-rates during this position with both squads. With Squad A these were recorded only on the last day of the observation, that is, on a restricted diet. With Squad B records were obtained on January 6 before the subjects had begun the low diet, and again on January 28, the last day of the greatly reduced diet. These pulse-rates are given for both squads in table 93.

On all these mornings the resting pulse was determined with the subject lying with minimum muscular activity in the group chamber before he rose. These values are also given for all the subjects in column a in table 93, for comparison with the standing pulse-rates. The figures, so far as Squad A is concerned, present no abnormalities and show low values similar to those noted on the respiration apparatus at Springfield on the two days preceding. (See table 80.) Values below 40 are found with 5 subjects in each squad.

The pulse measurements for the standing position in the experiments with the portable respiration apparatus, which in some cases were made several hours after the pulse measurements in the group chamber, are given in column b of table 93 and show increments for all of the subjects. The increments of the standing pulse over the lying pulse are given in column c. The greatest increment for Squad A is with Can, whose pulse rose from 48 to 84, i. e, 36 beats. The smallest increments were noted with Bro and Mon, of 5 each. The average increment is 17, if we exclude the large increment of Can in averaging.

It is unnecessary for us to go to earlier literature for a base line or for comparisons, as data were obtained with Squad B on normal and on reduced diet and in both positions. These values are given in the lower part of table 93. Attention may first be called to the fact that the pulse-rates for January 28 were invariably lower than those for January 6, when the men were on normal diet. Especial emphasis must be laid upon the increments due to standing, which are recorded in column c of table 93. The highest increment on normal diet is with Sne, with an increment of 41 beats, i. e., a rise from 48 to 89 beats. If we exclude this high value for Sne the average increment for Squad B with normal diet on January 6 would be 18. It thus appears that the increment due to change from the lying to the standing position was essentially the same on the reduced diet with Squad A as with that on normal diet with Squad B. The increments on reduced diet with Squad B (see January 28) range from 31 with Sne, who likewise showed the highest increment on normal diet, to 9 with Wil. Excluding Sne, we find the average increment on reduced diet to be somewhat less than 20, which is in full conformity with that noted for Squad A.

Table 93. - Comparison Of Pulse-Rates Of Subjects In Lying And Standing Positions, Subjects Without Food From 11 To 19 Hours 1

1 The time when the pulse was observed for the standing position varied according to the order in which subjects were used. 2 Increase over lying for Can and Sne omitted from averages.

3 The value of 74 for Can is an average of 81 (standing outside chamber) and 67 (standing on treadmill in chamber); likewise 67 for Sne is an average of 72 and 62. 4 McM, Jan. 6; pulse-rate, lying, 63; standing at portable, 80; increase over lying, 17; standing before walking, 84.

5 Lon, Jan. 28; pulse-rate, lying, 35; standing at portable, 52; increase over lying, 17.

Although the abnormally high increases for Can on February 3 and for Sne on January 6 and January 28 were eliminated from the averages, and the average increment for the standing position remains essentially the same on all three days, namely, 17, 18, and 19 beats, it can be seen that including these men in the average would but slightly alter the differences between these increases, and the increment due to change in position from lying to standing was practically the same under normal conditions and with reduced diet conditions. The normal values in this case are, however, represented by only one day (January 6) and the reduced diet by two days (January 28 and February 3) with different squads. Special attention should be called to the low averages for the basal pulse on the reduced diet days, these being 45 for Squad A and 40 for Squad B.

These increases are expressed in actual pulse beats, but it should be noted that the percentage increase is very considerably greater during the restricted diet than with the normal diet. Thus with Squad A the increase of 17 beats on February 3 with the basal value of 45 represents a percentage increase of 37.8 per cent. With Squad B on reduced diet (January 28), the increase of 19 on a basal value of 40 represents 47.5 per cent, while with Squad B on normal diet (January 6) the increase of 18 on a basal value of 56 represents 32.1 per cent increase, a materially lower figure.

In general, it can be seen that a change in position from lying in the group respiration chamber to standing with the portable respiration apparatus leads to an increase in pulse-rate of not far from 18 beats, an increment which is slightly greater in absolute terms and considerably greater in percentages with reduced diet than with normal diet. These differences, however, are not to be confused with the absolute height of the pulse-rate, which is much lower on the reduced days than on the normal days, this being shown more clearly with Squad B than with Squad A.