CHARACTER OF KATABOLISM 97 
of 1 gram of glycogen, 3 the heat of combustion of 1,558 calories would corre- 
spond to 368 grams of glycogen. Inasmuch as the respiratory quotient does 
not show a marked falling off as the work progressed, it is reasonable to sup- 
pose that at the cessation of work there was still a considerable supply of 
glycogen in the body and that the above calculated amount (368 grams) 
represents the minimum rather than the maximum. 
It is greatly to be regretted that the resting value in the post-absorptive 
condition was not determined on this man both before the experiment began 
and after the experiment ended. As a matter of fact the proper determination 
of the post-absorptive resting value usually requires about 2 hours, namely, one- 
half hour period of lying before the experiment begins, and approximately 
one-half hour for each experimental period. Inasmuch as in this experiment it 
was especially designed to have the subject ride to his maximum capacity, it was 
obviously important that the experiment should begin as early as possible 
in the morning. When it is considered that this enormous amount of muscular 
work was carried on without any food in the stomach, it can be seen that the 
subject was capable of very great muscular exertion. The protocols of the 
experiment b show that the work was very easily done by the subject for the 
first 2 hours of the period, but he then began to show slight and increasing 
signs of fatigue and at the end of the experimental period was thoroughly 
exhausted. The perspiration was very profuse during the whole experiment. 
The last period in which the respiratory exchange was determined was but 
6 minutes and 55 seconds in length instead of 10 or 11 minutes, like the other 
periods of work. During this period the subject was distinctly unable to 
keep the pace with which he had begun. When the subject finished work 
and his mouth was removed from the mouthpiece, it was noted that he was 
in a state of absolute collapse. When questioned, the subject reported that 
he felt completely exhausted, with a constant struggle for breath at the end 
of the experiment. As it was thought that the labored respiration might pos- 
sibly be due to the fact that the air in the circuit contained too small a per- 
centage of oxygen, analyses were immediately made and the air was found to 
contain 22.5 per cent of oxygen. Tests for unabsorbed carbon dioxide were 
negative in all periods. We have in this experiment, therefore, a case of 
simple exhaustion from excessive muscular work. It has been computed else- 
where c that the muscular work accumulated to 208,000 kilogrammeters. 
It is of interest to compute the distance that would have been covered by 
this man provided he had ridden an ordinary bicycle. During the entire 
period of work he made 22,482 revolutions of the pedal. The ratio of the 
number of teeth on the large sprocket to those on the smaller sprocket being 
3.25: 1, the copper disk was therefore rotated 73,066 times. The brake-effect 
with which the subject was riding, i. e., 1.5 amperes through the magnet, 
was in his judgment somewhat greater than that experienced in riding in a 
6-day bicycle race. Repeated tests have shown that this brake-effect or 
resistance would be secured for this subject by considerably less current, 
namely, 1.25 amperes. It is reasonable to suppose that the resistance would 
therefore be equal to that riding over a fairly good country road on a still 
day. Assuming that the wheel had a standard diameter of 28 inches (71 
centimeters), a simple calculation shows that the work done was equivalent 
« Benedict and Emery, Am. Journ. Physiol., 1911, 23, p. 301. *> See table 80, p. 66. « See p. 92. 
