GASEOUS METABOLISM DURING WALKING. 543 



decrease in heat output when standing was found with all subjects. 

 The heat output above standing, i. e., that specifically involved in the 

 work of walking, was decreased in all but 3 cases. A striking excep- 

 tion is the case of Fis, with whom there was an increase of 15.4 per cent; 

 there were also increases with Har and Sne. The averages show a 

 decrease from 2.95 calories on January 6 to 2.62 calories on January 28. 



Of special significance is the total heat required for walking 10 km. 

 This was almost alwaj^s largely decreased, the two exceptions being 

 the increase for Fis of 3.4 per cent and the insignificant change of 0.4 

 per cent with Sne. On the average these men as individual organisms 

 were able to walk 10 km. at a very considerably reduced expenditure of 

 energy. At the end of 20 days the average individual required for 

 walking 10 km. a total of 535 calories. This is a decrease on the aver- 

 age of 87 calories in the total heat required in walking this distance, or 

 approximately 14 per cent, and represents a real saving for the trans- 

 portation of the individual over a given distance. 



Owing to the unusual physiological interest in the efficiency of the 

 human organism as a machine, the values for the heat per horizontal 

 kilogrammeter have especial significance. It is seen that this value 

 is in some instances increased and in others decreased. The most 

 prominent increases are those of 19.7 per cent with Fis and 16.1 per 

 cent with Sne. The most prominent decreases are those of 24.6 per 

 cent with Kim, 27.9 per cent with Tho, 17.0 per cent with Wil, and 

 15.3 with Ham. It is extremely unfortunate that it is necessary to 

 take the general picture from a series of observations that vary as 

 widely as do these. Nevertheless, it seems reasonably clear that 

 the average value found prior to reduction on the normal day of 0.592 

 when compared to the average reduction found on January 28 of 0.565 

 represents a real, though relatively slight, decrease. In brief, of the 

 11 subjects tested on the two days, 4 show an increase, 1 shows prac- 

 tically no change and 6 show a decrease in this factor. 



From the average heat output with the subject standing and the 

 heat output over and above standing shown in table 141, it is possible 

 to compute approximately the distribution of the heat saving between 

 the standing and walking requirements. It is seen that the decrease 

 in the heat output for standing for the two dates was 0.27 calorie and 

 the decrease in the heat output required on walking over and above that 

 required for standing was 0.33 calorie. Of the total saving, then, of 0.60 

 calorie, that on the standing constituted 45 per cent and that on the 

 walking 55 per cent. These figures have some interest, though the 

 individual varia,tions are wide. Six of the 11 subjects, however, 

 showed that about 30 per cent of the saving was on the standing metab- 

 oHsm and 70 per cent on the walking metabohsm. 



While the reduction in body-weight in part explains the pronounced 

 reduction of 14 per cent in the energy required for walking 10 km., 



