162 
MUSCULAR WORK 
of about 1 hour, the total period of muscular activity being approximately- 
one hour less than that of the professional subject M. A. M. in the experiment 
of March 15 previously referred to. On the other hand, it should be stated 
that, in the case of N. B., the riding followed a substantial meal while all of 
the experiments with M. A. M. were made without food, the beginning of 
work in all cases being not less than 12 hours after the last meal. It is thus 
seen that in the experiment with M. A. M. on March 15, when the riding pe- 
riods ended, the subject had been without food in the] stomach for at least 18 
hours. As shown elsewhere in this report, the amount of work done during 
this time has been computed as probably being equivalent to not less than 
a 100-mile bicycle ride over ordinary roads, i. e., a "century run" before 
breakfast. 
As already noted, the mechanical efficiency does not vary greatly with 
different subjects; hence, instead of comparing the amount of work done, 
it is possible and quite logical to compare the amounts of oxygen consumed 
or the heat production computed indirectly for different individuals. Thus 
the great error due to the inability to calculate correctly the amount of ex- 
ternal muscular work performed is eliminated in these comparisons. The 
oxygen consumption during severe muscular work has been determined in a 
number of instances and the results have been tabulated in table 134. All 
of these determinations were made by the Zuntz method and by Zuntz, 
or Durig, or their associates. 
Table 134. — Comparison of the oxygen consumption during various forms of muscular 
work, as determined by the Zuntz method. 
Name of subject. 
Kind of work. 
Oxygen 
consump- 
tion per 
minute. 
Name of subject. 
Kind of work. 
Oxygen 
consump- 
tion per 
minute. 
c.c. 
1,539 
2,280 
2,037 
2,194 
1,863 
1,542 
2,307 
1,197 
Mountain-climbing 
Do 
c.c. 
2,318 
2,245 
2,662 
2,584 
2,674 
2,130 
2 3,000 
3 2,850 
. . .Do 
Do. . . 
Do. . 
Do 
Do... 
Do 
. . . Do 
N. B.i 
Bicycle-riding 
Do 
L. Zuntz 
Turning crank 
M. A. M. 1 
M. A. M. 1 
Do 
1 For comparison we give three values obtained on the bicycle ergometer. 
2 For 15 minutes. 3 For 1 hour 10 minutes. 
It is thus clear by every method of comparison that the subject M. A. M. 
performed an extraordinary amount of work and that his metabolism was 
elevated to an abnormally high degree. When it is considered that this high 
elevation persisted not simply for experimental periods of a few seconds or 
even 15 minutes, but for an hour or more, and that these long experiments 
were carried out by the subject without food in the stomach, it will be seen 
that this subject not only had great strength but very great endurance, and 
that the amount of work performed was considerably greater than that done 
in the most active mountain-climbing. 
o See p. 97. 
