LOCOMOTION 



373 



287. Expenditure of Energy in Locomotion- Walking. The ex- 

 penditure of energy in walking is measured by the consumption 

 of oxygen in calories. The dynamic expenditure is the excess of 

 that consumption over that of the subject when at rest. 



This study commenced with the striking investigations of 

 Zuntz, whose book ( l ) received the highest approbation from 

 German military authorities. 



His experiments were carried out on five subjects of from 1-70 

 m. to 1-81 m. in height, and weighing from 65 to 80 kilogrammes. 

 As an example one will be chosen from them weighing 65 kilo- 

 grammes (the average weight of an adult), his height being 1-69 

 m., and the length of the lower limb equal to 0-86 m. 



When walking at a speed of 4,588 metres per hour, the dynamic 

 expenditure of this subject was -574 small calories for each kilo- 

 gramme of his weight per metre covered. We have called this 

 the metre-kilogramme, which, in this case, is equivalent to slightly 

 more than half a small calorie. 



From the whole of his experiments Zuntz found an average of 

 518 small cal- 



pfif MKg. 



ories per metre- 

 kilogramme 



The writer ( 2 ) 

 obtained, under 

 similar condi- 

 tions an average 

 of -506 small cal- 

 ories, which re- 

 sult is con- 

 firmed by other 

 investigators. ( 3 ) 



The s p e ed 

 profoundly 

 modifies the ex- 

 penditure o f 

 energy, as will 

 be seen from fig. 

 268. Between 

 2-9 km. and 8-9 

 km. per hour, it 



1*0 

 0*9 

 0-8 

 0*7 

 T6 

 0-5 



2-4 3'6 



7-2 8*4 Km. 



FIG. 208. 



Dynamic expenditure per metre-kilogramme 

 at different speeds. 



( 1 ) Zuntz and Schumburg, Studien."zu einev Physiologic des Marsches, 

 Berlin, 1901 (361, pp. 8vo). 



( 2 ) Jules Amar (Journ. de Physiol., March 1911, p. 212). 



( 3 ) Leo Zuntz, A. and I. Loewy (Pfluger's Arch., vol. Ixvi., p. 477) ; W. 

 Kolmer and E. Brezina (Biochemische Zettsch., vol. xxxviii., p. 129, 6th Tan., 

 1912). 



