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CARNEGIE INSTITUTION OF WASHINGTON

PUBLICATION No. 187

THE UNIVERSITY PRESS, CAMBRIDGE, U. S. A.

PREFACE.

The experimental evidence secured in connection with this research was made possible only through the active co-operation and personal interest of the gentlemen who acted as subjects. Our thanks are due to Mr. Kurt H. Arndt, Mr. J. J. Currie, and especially to Mr. H. L. Higgins and Mr. J. E. Fitzgerald, all of the laboratory staff. Mr. Fitzgerald furthermore assisted in practically all of the experiments on others than himself. We are indebted to Dr. W. G. Anderson, Director of the Yale University Gymnasium, not only for the physical measurements on some of our subjects, but likewise for his co-operation in certain of the tests. The extraordinary interest and fidelity to the routine exhibited on the part of the professional subject, Mr. Melvin A. Mode, should not pass without special comment. It would have been impossible to conduct a series of experiments of this type without the intelligent co-operation of the subject. The complicated tables in the report have received the careful preparation of Mr. W. H. Leslie, and the entire manuscript has had the editorial supervision of Miss A. N. Darling. To all of these co-workers we wish to

express our thanks.

NUTRITIon LABoratoRY, CARNEGIE INSTITUTION of WASHINGTON,
Boston, Mass., April 12, 1913.

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CONTENTS.

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PART III.

Discussion of results..

The character of the katabolism as affected by muscular work . ......

Determination of the respiratory quotient ...,

Errors incidental to the determination of the carbon dioxide production

Errors incidental to the determination of the oxygen consumption ....

Physiological sources of error in gas measurements ..........

The basal metabolism .

The normal resting metabolism as determined in this research.

The character of the katabolism during muscular work as indicated by the re-

spiratory quotient .

Theories of Chauveau and Zuntz as to the character of the katabolism during

muscular work . . . . . . . . . . . . . . . . . .

The respiratory quotients of the bicycle ergometer experiments and their sig-

nificance . . . . . . . . . . . . . . . . . . . . . . . . . .

General comparison of the respiratory quotients ............

Influence upon the respiratory quotient of increasing amounts of work ..

Influence upon the respiratory quotient of variations in the amount of car-

bohydrates in the diet.

Subsidiary evidence with regard to the effect of muscular work on the char-

acter of the katabolism.

Influence upon the respiratory quotient of variations in the amount of work

done .....

Conclusions regarding the influence of muscular work upon the character of

the katabolism ..

........ ..

Estimates of the amount of carbohydrates in the body ..........

Urine excretion in experiments with muscular work ...........

Mechanical efficiency of the human body ..

Previous studies on the mechanical efficiency of the human body ...

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The Unit Oi emciency.

The unit of efficiency

. . . . . . . . . . . . . . . . . . . . . . . . .

112

Gross and net efficiency .

112

Methods of computing the net efficiency.....

Comparison of basal metabolism in bicycle ergometer experiments ...... 115

Increment in metabolism due to changing from a lying to a sitting position . 115

Increment in metabolism due to a change in position from lying on a couch to

sitting on a motor-driven ergometer ...............

Increment in metabolism due to a change in position from lying on a couch to

riding on an ergometer with no load and no motor .........

Increment in metabolism in no-load experiments due to a change from a motor-

driven ergometer to riding without motor . ....

Gross and net efficiency of subjects in respiration experiments with the bicycle

ergometer ...

Efficiency in work experiments based on values obtained in experiments with

the subject sitting on the bicycle ergometer ....

126

Efficiency in work experiments based on values obtained in no-load experiments

without motor ...

Efficiency in work experiments based on values obtained in no-load experiments

with a motor-driven ergometer

Efficiency in work experiments based on values obtained with a current of 0.5

ampere . . · · : · Lii:

Efficiency in work experiments based upon values obtained with a current of

135

General consideration of the experimental data obtained with the professional

subject, M. A. M. ..

Relationships between speed and efficiency ..

Comparison of the efficiency in the earlier and later experiments with the

ergometer. . . . . . . :,:,:

143

Relationship between efficiency and the character of the diet.

145

Physiological effects of muscular work ...................

147

Mechanics of respiration ...

147

Ventilation of the lungs as affected by muscular work ...

Carbon-dioxide content of the alveolar air after muscular work .

Collapse from excess of carbon dioxide in the ventilating current .

150

Pulse-rate . . . . . . . . . . . . . . . . . . . . . . . . . . .

Body-temperature . . . . . . . . . . . . . . . . . . . . . . .

The maximum working capacity of man .......... ...... .

160

The after-effects of muscular work ........,

163

An attempted analysis of the components of the total energy transformations

incidental to severe muscular work. ............... 173

:::............

147

149

153
157

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