PART II.

STATISTICS OF EXPERIMENTS.

In this series of experiments, 7 subjects were used. The statistics as to their occupation, age, height, and average weight without clothing are given in table 5. With the single exception of M. A. M., none of the subjects had any special training in bicycle riding or had ever ridden to excess, nor did any of them own bicycles; for many months previous to the experiments, they had ridden only intermittently, if at all.

TABLE 5.-Statistics of age, height, and average weight of subjects.

The subject M. A. M., with whom most of the experiments were made, began riding as an amateur in 1896 and as a professional bicyclist in 1901, continuing until 1910. Between 1901 and 1905 he took part in 5 motor-paced races; in 1905 he rode in a 6-day bicycle race in New York City and in a second in 1907. He also rode in numerous smaller races and kept in general good condition up to the time of the beginning of the experiments. While the subject never took a regular training course, he exercised regularly in a gymnasium between 1896 and 1908, and practiced boxing considerably, although with no special success. As in 1907 his nose was broken, the boxing practice was discontinued. His maximum weight previous to the research was in May 1911, when he weighed 66.7 kilograms. During the research he was twice examined physically by Dr. W. G. Anderson, of Yale University. As a result of the examination on March 4, 1912, Dr. Anderson said that the subject was remarkably well developed, particularly in the abdominal and thigh muscles, but drew attention to the somewhat surprising fact that the lower leg-muscles, particularly the gastrocnemii, were not well developed. A second examination was made by Dr. Anderson on April 25, 1912, the results of which are given in table 6. Information regarding the dietary habits of the subject is given on page 80.

In presenting the statistics of the experiments, we have grouped them under three heads: (1) lying vs. sitting experiments; (2) no-load experiments. both with and without motor; (3) work experiments. The general character of each class of experiments has been described in some detail on pages 31 and 32. In these groups, the experiments have been arranged first according to subject and then for the most part chronologically. Reference to the statistical details of any experiments may thus be readily made.

The data for the experiments are given in tabular form and include the carbon dioxide eliminated per minute, the oxygen absorbed per minute, the respiratory quotient, and the average pulse and respiration rates, the record for the respiration-rate usually representing the result of but one observation in each period. In the statistics for the no-load experiments, the records of the number of revolutions per minute have been added, and in those for the work experiments, both the revolutions per minute and the current used through the magnetizing field. All necessary details not included in the tabulated material are given in footnotes.

Height

TABLE 6.-Measurements of M. A. M. Date, April 25, 1912. Age, 32 years.

Girth of

Left thigh

54.1

Right calf

34.3

The respiratory exchange was determined with a respiration apparatus which has already been fully described in the previous section of the report. The work was done on a bicycle ergometer; two ergometers were used, designated respectively as ergometer I and ergometer II, both of which are described on pages 25 to 27. Ergometer I was used in the experiments up to January 23, 1912, all subsequent experiments being made with ergometer II. The general routine of the experiments is given on pages 31 and 32, together with special details as to methods. The subject was without food in practically every case, the observations being made in the post-absorptive state, i.e., at least 12 hours after the last meal.

LYING VS. SITTING EXPERIMENTS.

These experiments were made for the special purpose of obtaining the basal metabolism; the statistical details are given in tables 7 to 15 inclusive. In the lying experiments, the subject lay as quietly as possible upon a couch, no observations being made until the conditions were absolutely normal for a rest period. The experiment usually covered three 15-minute periods, with intermissions of varying lengths. Lying experiments were made almost every day as a part of the regular routine; the statistics for those made in comparison with the no-load and work experiments are given with the statistics under these particular heads.

In the sitting experiments, the subject sat motionless upon the bicycle ergometer in position for riding. The general routine as to preliminary periods and length was the same as for the lying experiments. As will be seen in many of the notes appended to the tables, the subjects found the enforced quiet of this position somewhat irksome. An attempt was made with some of the subjects to relieve the constraint by supporting the pedals with a block of wood, or otherwise, but the experiments with the subject M. A. M. were all made without such support.

TABLE 7.-Results with subject J. E. F. (without food). (Ergometer I.)

1 The subject had walked 12 miles in the course of the preceding 24 hours. His dinner the night before was an ordinary meal, varied in character.

2 The subject sat on the ordinary seat of the ergometer with his feet resting on blocks placed on the floor.

3 The subject sat on the ergometer for half an hour before the period began.

4 The subject complained that the position was very tiring.

5 The subject said that he felt extremely stiff and that he was tired.

TABLE 8.-Results with subject E. P. C. (without food). (Ergometer I.)

1 The pulse-rate was not obtained.

2 The subject sat on the ordinary seat of the ergometer with his feet resting on blocks placed on the floor. 3 The subject sat on the ergometer about half an hour before the period began. He was quiet during the period except for removing his hands from the handles and placing them on his knees, and then back again to the handles.

4 The subject had the position of the handles altered slightly.

TABLE 9.-Results with subject K. H. A. (without food).1 (Ergometer I.)

1 The subject had eaten heavily the day before, as late as 10.00 p.m. 2 The subject sat on a broad wooden seat with his feet on a rest attached to the front fork of the machine. 3 The subject sat on the ergometer for half an hour before the period. He had the mouthpiece in his mouth 20 minutes before the period and was in the usual cramped position. Between the sitting periods the subject was allowed merely to release his mouth a minute or two and then returned to the customary position.

4 The subject was distinctly hungry while sitting up. This feeling was quite lacking while he was lying down.

TABLE 10.-Results with subject M. A. M. (without food). (Ergometer I.)

1 A screen was used to shut off the subject's view of the rubber diaphragm. 2 The subject's respiration was rather irregular and shallow throughout the period. Occasional deep breaths were taken. There was also a curious irregularity in breathing during the preceding period, extremely shallow.

3 The subject desired to urinate and was in some discomfort. He was afraid to breathe deeply, as an abdominal breath was followed by a full movement of the diaphragm with subsequent pressure on the bladder. 4 The subject sat on the ordinary seat with his feet on unsupported pedals, i. e., with the disk perfectly free. 5 The subject sat on the ergometer 20 minutes before the period. He breathed freely and deeply. His feet and legs were remarkably steady throughout.

TABLE 11.-Results with subject M. A. M. (without food).

(Ergometer I.)

1 The respiration rate was rapid at the start but was more regular than on Dec. 7. It became shallow in the third period. The subject desired to urinate at the beginning of the third period but did not till the end of the fourth period.

2 The subject lay quietly and was comfortable. He urinated before the experiment. The heart-beat was steady and slow. The pulse-rate at 8h 15m a.m. was 76.

3 The subject sat on the ordinary seat with his feet on unsupported pedals, i. e., with the disk perfectly free. 4 The subject sat on the ergometer for 30 minutes before the period began. The pulse-rate at 10b 25m a.m. was 76, the subject's feet being on a foot-rest. At 10h 27m a.m. he lowered his feet to the pedals, and put his mouth to the mouthpiece. The pulse-rate at 10h 29m a.m. was 84; at 10h 32m a.m., 10b 34 a.m., and 10h 36m a.m., it was 86; at 10h 38m a.m. it was 87.

5 The subject found that sitting perfectly still was very tiring. He complained of dry air. This was found to be due to the fact that the water in the moistener was low.

1 The subject sat on the ordinary seat with his feet on unsupported pedals, i. e., with the disk perfectly free. 2 The subject sat on the ergometer at 8 a.m. The pulse-rate at 8h 15m a.m., 8b 22m a.m., and 8h 28m a.m. was 84. Subject put his mouth to the mouthpiece at 8h 22m a.m. He sat remarkably steady, and preferred to have his feet on the pedals rather than on the rest. In the second period the handle bars were uncomfortable, and later the saddle hurt him. He had a cloth covering on the saddle during the third period.

3 The subject lay down at 9h 45m a.m. He lay perfectly quiet and was quite comfortable.

4 The timing of the beginning of this period may not have been exactly correct, as it was difficult to follow the subject's breathing.