MECHANICAL EFFICIENCY OF THE HUMAN BODY 
133 
this have already been freely mentioned in the previous discussions. It 
seemed desirable, therefore, that experiments should be made in which the 
subject should perform light work, sufficient in amount to insure a reasonably 
regular rotation of the pedals, and to eliminate all tendency to back pedal 
or to race. Accordingly a series of experiments was carried out in which the 
current through the armature was adjusted at 0.5 ampere. This was a very 
light load, and, indeed, somewhat lighter than the subject really preferred 
for comfort and complete muscular coordination; nevertheless there was con- 
siderably more resistance than with "no load" and the results furnish a 
reasonably constant base-line. In other experiments the subject rode with 
the resistance produced by a current of 1.5 amperes, and a comparison can 
logically be made of the results obtained in all experiments with these two 
resistances in which the revolutions per minute were essentially the same. 
Table 121. — Efficiency of subjects in respiration experiments with bicycle ergometer with, a 
current of 1.5 amperes. 
[Basal values obtained in experiments with current of 0.5 ampere.] 
Oxygen in- 
take per 
minute dur- 
ing work. 
Heat output per 
minute during work. 
Revolutions 
per minute. 
Heat equivalent of 
external work per 
minute. 
Effici- 
Date. 
Subject. 
(a) 
G>) 
(c) 
(d) 
to 
(/) 
<*) 
m 
(0 
to 
ency. 
Cur- 
rent 
Cur- 
rent 
Cur- 
rent 
Cur- 
rent 
Increase 
over 
Cur- 
rent 
Cur- 
rent 
Cur- 
rent 
Cur- 
rent 
Increase 
over 
i xioc 
e 
1.5 
0.5 
1.5 
0.5 
work at 
1.5 
0.5 
1.5 
0.5 
work at 
amp. 
amp. 
amp. 
amp. 
0.5 amp. 
e -d 
amp. 
amp. 
amp. 
amp. 
0.5 amp. 
h — i 
1912. 
c.c. 
e.e. 
cats. 
cals. 
eels. 
cats. 
czl. 
cals. 
p.ct. 
Mar. 16 
J. J. C. 
1,808 
1,055 
8.97 
5.05 
3.92 
72 
71 
1.60 
0.48 
1.12 
28.6 
1,886 
1.055 
9.20 
5.05 
4.15 
72 
71 
1.60 
.48 
1.12 
27.0 
Mar. 7 
K. H. A. 
2,060 
1,076 
10.02 
5.19 
4.83 
79 
79 
1.74 
.52 
1.22 
25.3 
1,949 
1,076 
9.67 
5.19 
4.48 
80 
79 
1.76 
.52 
1.24 
27.7 
Apr. 3 
2,015 
1,057 
9.92 
5.15 
4.77 
79 
79 
1.73 
.52 
1.21 
25.4 
2,147 
1,057 
10.41 
5.15 
5.26 
79 
79 
1.74 
.52 
1.22 
23.2 
Mar. 2 
J. E.F. 
1,648 
876 
8.10 
4.341 
3.76 
72 
75 
1.59 
».50 
1.09 
29.0 
1,801 
876 
8.82 
4.34 
4.48 
79 
75 
1.75 
.50 
1.25 
27.9 
Mar. 16 
1.719 
876 
8.42 
4.34 
4.08 
71 
75 
1.57 
.50 
1.07 
26.2 
1,824 
876 
8.84 
4.34 
4.50 
71 
75 
1.58 
.50 
1.08 
24.0 
Mar. 5 
E. P. C. 
1,498 
829 
7.40 
3.90 
3.50 
65 
65 
1.43 
.43 
1.00 
28.6 
1,418 
829 
7.10 
3.90 
3.20 
64 
65 
1.41 
.43 
.98 
30.6 
Feb. 28 
M.A.M. 
2,356 
1,168 
11.77 
5.68 
6.09 
108 
100 
2.18 
.55 
1.63 
26.8 
2,101 
1,168 
10.49 
5.68 
4.81 
97 
100 
2.04 
.55 
1.49 
31.0 
2,144 
1,168 
10.82 
5.68 
5.14 
100 
100 
2.07 
.55 
1.52 
29.6 
Max. 4 
2,290 
1,216 
11.33 
5.95 
5.38 
104 
104 
2.15 
.55 
1.60 
29.7 
2,259 
1,216 
11.32 
5.95 
5.37 
105 
104 
2.16 
.55 
1.61 
30.0 
2,375 
1,216 
11.72 
5.95 
5.77 
103 
104 
2.12 
.55 
1.57 
27.2 
Mar. 12 
1.564 
806 
7.56 
3.89 
3.67 
72 
72 
1.59 
.48 
1.11 
30.2 
1,520 
806 
7.41 
3.89 
3.52 
71 
72 
1.57 
.48 
1.09 
31.0 
1,534 
806 
7.51 
3.89 
3.62 
71 
72 
1.57 
.48 
1.09 
30.1 
Mar. 13 
1,513 
860 
7.44 
4.22 
3.22 
70 
73 
1.56 
.49 
1.07 
33.2 
1,631 
860 
7.87 
4.22 
3.65 
70 
73 
1.57 
.49 
1.08 
29.6 
1,556 
860 
7.66 
4.22 
3.44 
70 
73 
1.56 
.49 
1.07 
31.1 
Mar. 14 
1,550 
818 
7.59 
3.95 
3.64 
71 
70 
1.57 
.47 
1.10 
30.2 
1,526 
818 
7.53 
3.95 
3.58 
71 
70 
1.57 
.47 
1.10 
30.7 
1,559 
818 
7.64 
3.95 
3.69 
71 
70 
1.57 
.47 
1.10 
29.8 
Mar. 18 
1,541 
823 
7.55 
3.96 
3.59 
71 
71 
1.57 
.48 
1.09 
30.4 
2,315 
1,168 
11.35 
M9 
5.67 
102 
100 
2.12 
1 .55 
1.57 
27.7 
2,320 
1,168 
11.39 
5.68 
5.71 
102 
100 
2.11 
.55 
1.56 
27.3 
1 Average of results obtained in the experiment of Mar. 16 with this subject. 
1 Average of results obtained in the experiment of Feb. 28 with this subject. 
In discussing the previous tables, it has been pointed out frequently that 
there appeared to be some intimate relationship between the speed and the 
total amount of work performed, and the results show that only experiments 
with constant speed should be compared. Accordingly in table 121 we have 
included only those experiments with the different subjects in which essen- 
