226 



METABOLISM DURING WALKING. 



grade, in the performance of this work there was less economy in the 

 metabolism with the lower grade. 



Thus, from the curves for W. K., we rind that in performing 700 

 kg. m. of work on a 25 per cent grade, he would produce 1,540 c. c. of 

 carbon dioxide, while for the same amount of work on a 20 per cent 

 grade the carbon-dioxide production would be 1,665 c. c. A like 

 relation is seen to exist in the carbon-dioxide curves for E. D. B., 400 

 kg. m. of work on a 15 per cent grade costing 920 c. c. of carbon dioxide, 

 whereas on a 10 per cent grade it would cost E. D. B. 1,030 c. c. 



CO, 

 c.c. 



3000 

 2800 

 2600 

 2400 

 2200 

 2000 

 1800 

 1600 

 1400 

 1200 

 1000 

 800 

 600 



2-dX 



3.0 



D.10.0 

 15.0 



20.0 



400 

 Kg.ms. 200 400 600 800 1000 1200 1400 1600 



FIG. 17. Total carbon-dioxide production of E. D. B., referred to kilogrammeters 

 of work performed in walking on different grades. (Values per minute.) 



The oxygen consumption per minute for the same four men has also 

 been plotted on the basis of kilogrammeters of work, and the curves are 

 given in figures 18 and 19. The general picture of the relationships is 

 similar to that in figures 16 and 17, with reasonable uniformity between 

 the increase in the oxygen consumption and the increase in the amount 

 of work accomplished. The curves for E. D. B. for the higher grades 

 (25 per cent and over) exhibit a tendency to change slightly in direction 

 as compared with those for the lower grades. 



While the range of work with W. K. was less than with E. D. B., the 

 single curve for this subject above 20 per cent (that for a 25 per cent 

 grade) indicates a similar tendency to change in direction at this point. 

 The relative position of the curves with both subjects is usually like 

 that found for the carbon-dioxide curves. With E. D. B., however, 



