92 
MUSCULAR WORK 
calories of external muscular work in 4 h 22 m of actual riding, 'this being 
equivalent to 208,000 kilogrammeters. Despite this enormous amount of 
muscular work, the respiratory quotient remained in the vicinity of 0.90 
throughout the experiment, while if there had been a material combustion of 
fat or a conversion of fat into carbohydrate, a considerably lower quotient 
than this would have been expected. Although the average quotient of 0.90 
does not indicate by any means a combustion exclusively of carbohydrates, 
it does indicate a combustion of material containing a considerable proportion 
of carbohydrates, since Magnus-Levy ° has shown that a respiratory quo- 
tient of 0.90 corresponds to a metabolism of 15 per cent of protein, 61 per 
cent of carbohydrates, and 24 per cent of fat, and that a respiratory quotient 
of 0.85 corresponds to a metabolism of 15 per cent of protein, 44 per cent of 
carbohydrates, and 41 per cent of fat. (See p. 96.) 
Table 97. — Respiratory quotients in experiments without food, light or moderate work 
preceding severe work. 
[Figures in light-face type represent accumulated work to end of period expressed in calories.] 
Calories of 
work per 
Date. 
Subject. 
minute 
Respiratory quotient. 
during 
period. 1 
1912. 
Apr. 3 
K. H. A. 
0.50 
1.65 
j 19 
1 0.88 
(111 
1 0.91 
30 
0.84 
148 
0.85 
Mar. 16 
J. E. F. 
.50 
1.65 
j 24 
1 0.93 
( 89 
1 0.89 
35 
0.92 
119 
0.85 
Mar. 12 
M. A. M. 
.50 
( 17 
t 0.85 
29 
0.82 
40 
0.84 
1.65 
(102 
1 0.84 
135 
162 
0.87 
0.89 
Mar. 13 
M. A. M. 
.50 
j 21 
1 0.92 
33 
0.88 
43 
0.88 
1.65 
(109 
1 0.91 
147 
190 
0.83 
0.91 
Mar. 15 
M. A. M. 
1.95 
( 77 
i 0.90 
163 
0.91 
251 334 416 
0.89 0.89 0.97 
489 
0.88^ 
Apr. 8 
M. A. M. 
1.30 
1 65 
! 0.89 
102 
0.87 
129 
0.87 
1.95 
(195 
j 1.00 
246 
283 
1.00 
0.91 
Apr. 9 
M. A. M. 
1.30 
1.65 
( 59 
\ 0.88 
(207 
i 0.98 
85 
0.88 
114 
0.90 
1 Approximate. 
2 During this period the external work per minute amounted to 1.734 calories. 
A special experiment made with M. A. M. on March 8, though not in- 
cluded in the table, may likewise be cited here as confirmatory evidence of 
the conclusions already drawn from these data. In this experiment the sub- 
ject rode for l h 45 m without load and with the ergometer driven by the motor. 
The respiratory quotient determined during this time was 0.82. There were 
then three periods of work in which on the average 2.10 calories of external 
muscular work per minute were performed. With 81 calories of accumulated 
external work, the respiratory quotient was 0.88, with 127 calories of accumu- 
lated work the respiratory quotient was 0.90, and with 177 calories of aecumu- 
o Magnus-Levy in von Noorden's Handbuch der Pathologie des Stoffwechsels, Berlin, 1906, 1, p. 207. 
