598 
PHYSIOLOGY: BENEDICT AND MURSCHHAUSER 
superimposed load, one meter in a horizontal direction is equivalent to 
0.55 gram-calorie. These workers hkewise noted the distinct influence 
of increased velocity upon the energy requirement for the same amount 
of work. 
Prior to a direct calorimetric study of the influence of walking in a 
horizontal direction, as well as the work of ascent and descent, the 
present study was made to elaborate the earlier researches on horizontal 
walking. A modified form of the universal respiration apparatus was 
employed and a specially designed treadmill. The factors measured 
were the oxygen consumption, the carbon-dioxide production, the respi- 
ration-rate, the distance walked, the number of steps taken by the 
subject, and the height to which the body of the subject was raised in 
the up and down motion of walking. The values for the resting metabo- 
TABLE I 
SUBJECT NO. 
AGE 
NUDE WEIGHT 
HEIGHT 
CARBON DIOXIDE 
PER MINUTE 
OXYGEN 
PER MINUTE 
HEAT- 
PRODUCTION 
PER MINUTE 
yrs. 
kilos. 
cm. 
CC. 
CC. 
cals. 
I 
29 
69.7 
180 
223 
280 
1.34 
II 
31 
68.3 
177 
214 
258 
1.25 
TABLE II 
SUBJECT 
NO. 
NO. OF PERIODS 
WEIGHT WITH 
CLOTHING 
AVERAGE RATE 
OF WALKING 
PER MINUTE 
INCREASE IN HEAT 
OUTPUT OVER 
STANDING 
HEAT OUTPUT PEE 
HORIZONTAL 
KILOGRAMMETER 
kilos. 
meters 
cals. 
gm.-cals. 
I 
53 
73.10 
75.9 
2.81 
0.507 
II. 
57 
71.45 
71.5 
2.52 
0.493 
lism as determined for both the lying and the standing relaxed positions 
were taken as base Unes for comparison with the values obtained with 
the subject while walking. A few experiments were made when the 
subject was walking at a high rate of speed and likewise when running. 
The preliminary observations were made on one subject by Dr. Carl 
Tigerstedt of Helsingfors during his short sojourn at the Nutrition 
Laboratory. A more extended investigation was carried out on a second 
subject with special emphasis upon change in velocity and the influence 
of food, including experiments with uncontrolled diet and diets con- 
taining a preponderance of protein, fat, or carbohydrate. A few experi- 
ments were prolonged for the purpose of studying the possible influence 
of fatigue. 
The metabohsm found for the standing relaxed position, with the 
subject in the post-absorptive condition, is given in table I, and for 
