PHYSIOLOGICAL EFFECTS 
161 
Magnus-Levy ,° on the basis of the research of L. Zuntz, 6 has recomputed the 
total work performed by the bicycle rider in R. C. Carpenter's report, his 
results being 20 per cent higher than those computed by Carpenter. 
Although for comparison with the results of this research, the data 
obtained in experiments with bicycle riders are of more value, nevertheless 
an interesting collection of calculations regarding the maximum work of 
man has been made by Blix. c Using an ingenious crank dynamograph de- 
vised by Sandstrom, Blix obtained certain results which he compared with 
those obtained with other forms of severe muscular work. These data have 
been recomputed by Magnus-Levy on the basis of kilogrammeters, d and for 
purposes of comparison, we have again recomputed them in terms of calories 
per minute of effective muscular work, and report them in table 133. 
Table 133. — Effective muscular work in various forms of activity, as reported by Blix. 1 
Kind of work. 
Length of work. Effec * ive muscular work 
^ per minute. 
Mountain-climbing, moderate work 
Many hours . . . 
1 to 2 hours . . . 
3 J minutes. . . . 
30 seconds 
15 seconds 
30 seconds 
4 seconds 
kgm. 
500 
750-1,000 
2,000 
2,400-3,600 
3,700 
4,300 
5,700-6,000 
cals. 
1.16 
1.74-2.33 
4.65 
5.58-8.37 
8.61 
10.00 
13.26-13.95 
Steep mountain-climbing, 100 meters. . . . 
Running up stairs, without load 
l Recomputed in kilogrammeters by Magnus-Levy, and by us in calories per minute. 
While the subject M. A. M. occasionally sprinted for short periods at a 
speed as great as 198 revolutions per minute, our observations deal almost 
exclusively with periods in which he worked at a constant rate for not less 
than 10 minutes and usually for approximately an hour. In such experiments 
he repeatedly produced 2.3 calories per minute of external muscular work. 
In discussing the muscular work of mountain-climbing, Magnus-Levy d 
states that he has often observed a herdsman in the Alps climb up in a direct 
ascent 800 meters in 1 hour, which he considers is equal to 60,000 kilo- 
grammeters, or 1,000 kilogrammeters per minute, this corresponding to 2.3 
calories per minute. It is thus seen that our subject M. A. M., when riding 
at the rate of 2.3 calories per minute, was performing work equal in amount 
to the severe work of the herdsman in the Alps; the experimental evidence 
shows that the subject M. A. M. on certain days maintained approximately 
this speed for an hour or more. 
One of the most striking illustrations of the staying qualities and the 
endurance of our professional subject is shown in the experiment of March 15, 
in which the external work performed was at the rate of 2 calories per minute, 
this rate being kept up without cessation for 43^ hours. This is the greatest 
sustained muscular work that we have thus far seen reported, although 
essentially this .amount of work was reported by Benedict and Carpenter 6 
as done by the professional bicycle rider N. B. On October 22, 1904, the sub- 
ject N. B. rode from 2 p.m. to 4 h 58 m p.m., with a preliminary riding period 
• Magnus-Levy, Physiologie des Stoffwechsel, in von Noorden's Handbuch der Pathologie des Stoffwechsels, 
Berlin, 1906, 1, p. 248. 
6 Leo Zuntz, Untersuchungen uber den Gaswechsel und Energieumsatz des Radfabren, Berlin, 1899. 
c Blix, Skand. Archiv, 1904, 15, p. 122. 
d Magnus-Levy, loc. tit., p. 247. 
t Benedict and Carpenter, loc. tit., pp. 30 and 31. 
