PREFACE. 



The following report presents the results of a series of experiments 

 carried out in continuation of a plan of study at the Nutrition Labora- 

 tory on the energy expenditure during muscular work, and supple- 

 ments the report of Benedict and Murschhauser: Energy Transforma- 

 tions during Horizontal Walking. 



The author is indebted to the Director, Dr. Francis G. Benedict, 

 for his constant interest and criticism as the work progressed, and to 

 Miss A. N. Darling for her painstaking supervision of the editorial 

 work in preparing the material for publication. He is also indebted 

 to Mr. Karl H. Brown for his interest and fidelity in the difficult task 

 of recording the pulse-rates and to Mr. William H. Leslie for much of 

 the labor involved in the calculations, and preparation of the tables. 



NUTRITION LABORATORY OF THE 



CARNEGIE INSTITUTION OF WASHINGTON, 



Boston, Massachusetts, April 23, 1921. 



Ill 



