68 



ENERGY TRANSFORMATIONS DURING HORIZONTAL WALKING. 



With subject I no such classification could properly be made and, 

 indeed, the observations after the ingestion of food were but few in 

 number. 



The metabolism with and without food are further compared in 

 table 9, to which is added the actual increase in the units of measure- 

 ment commonly employed for the various factors and the percentage 

 increase. From this table we see that as the result of a light meal the 

 carbon dioxide was increased 10.9 per cent, the oxygen consumption 

 12.2 per cent, and the heat output 11.8 per cent. After the heavy meal, 

 the percentage increase was essentially the same for all three factors, 

 i. e., 22.8 per cent. This percentage increment in the metabolism of 

 subject II after a heavy meal is almost identical with that noted for 

 subject I in the few experiments made with him. 



TABLE 9. Metabolism of subject II in the sitting position with and tvithout food. 



[Average values per minute.] 



J The pulse-rate was obtained in only one of the four periods after the light meal; in but two of 

 the five periods after the heavy meal. (See table 8.) 



One serious objection to this type of comparison, however, and an 

 objection that measurably lessens the mathematical value of the incre- 

 ment due to food, is the fact that the periods after the midday meal 

 followed the walking experiment in the morning, in which there was 

 considerable muscular activity. As a matter of fact, the long-con- 

 tinued walking experiments, in which the walking was done at a rapid 

 rate and the muscular activity was very severe, were not carried out 

 until later in the spring of 1914, and hence in all probability we have 

 not here to consider any great after-effect of the muscular activity of 

 the morning which persisted throughout the experiment in the after- 

 noon. Nevertheless, it is quite possible that at least a part of the 

 excess metabolism after the midday or "heavy" meal may be explained 

 by the fact that the subject had done considerable walking in the fore- 

 noon, while no such muscular activity preceded the after-breakfast 

 experiments. 



Of special significance here is the apparent striking relationship 

 between the percentage increment in the total metabolism and the 

 percentage increment in the pulse-rate. The increase in the heat- 



