MECHANICAL EFFICIENCY OF THE HUMAN BODY 
109 
Table 106. — Heat equivalent of muscular work and corrected amount of heat produced in 
experiments with A. L. L., 1 as reported by Benedict and Carpenter. (7 a.m. to 7 p. m.) 
Experiment. 
Date. 
(a) 
Heat equi- 
valent of 
muscular 
work. 
9) 
Heat 
pro- 
duced. 
T* (C) 
Heat pro- 
duced over 
resting 
metabolism. 
(d) 
Net 
efficiency. 
(oX100)-rc 
Work: 
No. 62 
1904 
Apr. 16-17 
Apr. 17-18 
Apr. 18-19 
Apr. 19-20 
Apr. 20-21 
Apr. 21-22 
Apr. 22-23 
Apr. 23-24 
Apr. 24-25 
cals. 
459 
458 
460 
460 
460 
458 
957 
cals. 
3,599 
3,578 
3,602 
3,657 
3,573 
3,518 
6,843 
1,203 
1,351 
cals. 
2,322 
2,301 
2,325 
2,380 
2,296 
2,241 
4,638 
p. ct. 
19.8 
19.9 
19.8 
19.3 
20.0 
20.4 
20.6 
No. 63 
No. 64 
Rest with food: 
No. 65 
No. 66 
1,277 
1 In deducting the heat production of resting metabolism from that in the work experiments, the averages of 
Nos. 65 and 66 were used. For the severe work experiment (No. 64), the heat production during the 
period from 7 a.m. to 4 a.m. of experiment No. 65 was used as the resting metabolism. This was found 
to be 2,205 calories. Deducting this from the total heat production of experiment No. 64 (6,843 cal- 
ories) leaves 4,638 calories as the heat production necessary to produce mechanical work, the heat 
equivalent of which is 957 calories. 
Table 107. — Heat produced in experiments with B. F. D. and E. F. S., as reported by 
Benedict and Carpenter. 
(a) 
(b) 
(c) 
(d) 
(«) 
(/) 
G?) 
Subject and 
date. 
Period. 
Heat 
pro- 
duced. 
No. of 
revolu- 
tions. 
No. of 
revolu- 
tions 
per 
minute. 
Cur- 
rent. 
Heat 
equivalent 
of muscu- 
lar work. 
Heat pro- 
duced over 
resting 
metabolism. 
Net 
efficiencv. 
(eXlOO-h/- 
B. F. D. 
cals. 
amp. 
cals. 
cals. 
p. ct. 
Work: 
Mar. 1, 1904 
7 a.m. to 7 p.m. 
4,085 
25,959 
60 
1.25 
600 
2,747 
21.8 
2, 1904 
7 a.m. to 1 p.m. 
1,963 
12,645 
56 
1.25 
292 
1,280 
22.8 
Rest with food: 
Mar. 3, 1904 
7 a.m. to 7 p.m. 
1,339 
... 
E. F. S.i 
Work: 
Mar. 5, 1904 
7 a.m. to 7 p.m. 
4,782 
26,495 
61 
1.25 
612 
3,382 
18.1 
1 No resting experiment with E. F. S. was made, as the subject left the city shortly after the conclusion of 
the work experiment. His body-weight was 80 kilos., and from a large amount of data obtained with 
other subjects, it is highly probable that his resting metabolism would have been not far from 1,400 
calories for the period from 7 a.m. to 7 p.m. Accordingly, this resting metabolism has been assumed 
in the computations. 
Finally, a series of experiments was made with a professional athlete, 
N. B., in which the metabolism was studied during short periods, usually 
V/2 to 3 hours in length. The subject, who was 35 years old, weighed 66 
kilograms, and was 172 centimeters in height, was one of the best-known 
professional bicycle riders in America. He was in excellent condition and an 
ideal subject for the experiment. The results, calculated on a one-hour basis, 
are abstracted in table 108. No data for oxygen consumption are given for 
the experiments made in October 1904, as the methods for the measurement 
of this factor had not then been perfected. Of special note is the net effi- 
ciency exhibited by this professional subject, the average being 21 per cent. 
