90 METABOLISM DURING WALKING. 



DISCUSSION OF RESULTS. 



The data given in the preceding section will be discussed in the gen- 

 eral order of standing, horizontal-walking, and grade-walking experi- 

 ments, considering first in each case the gaseous metabolism and the 

 heat-output, then the physiological effects of the work performed. For 

 such discussion reference will be made to tables in the statistical section 

 (see p. 42) from which, with few exceptions, material for the other 

 tables has been drawn. 



BASAL METABOLISM. 



While the special topic of this report is not basal metabolism, basal 

 values were obtained for all of our subjects, usually by other members 

 of the Laboratory staff, in experiments carried out for an entirely 

 different purpose. Ordinarily these values were determined with a 

 respiratory- valve apparatus or the universal respiration apparatus, and 

 not infrequently with the clinical respiration apparatus. 1 Many 

 observations were made in the comparison of the several methods, 

 particularly during the development of the clinical respiration appa- 

 ratus. The conditions in all of the experiments were those required 

 for basal values, namely, the subject was in the lying position, in a 

 post-absorptive condition, and with the greatest possible degree of 

 muscular repose. The values may thus be considered to be true basal 

 values. The data for all of the subjects except E. L. F. have already 

 been reported in abstract in the biometrical analysis of basal metabol- 

 ism measurements by Harris and Benedict. 2 



The basal-metabolism measurements were not used in the present 

 study, save for the purpose of comparing the metabolism of the sub- 

 jects in the lying position with the values for their metabolism when 

 they were standing, to determine the influence of the effort of standing. 

 (See table 22, p. 101.) Since these measurements of the basal metab- 

 olism were most carefully made, they should be recorded here, but 

 the average results only are reported. (See table 17.) 



In considering the values in table 17, it is obvious that the only re- 

 sults which contribute to the comparison of individuals with each other 

 are those which have been computed on the basis of unit of body-weight 

 or body-surface, for the individuals studied had materially different 

 body-weights. The respiratory quotients are, for the most part, con- 

 siderably above the quotient normally ascribed to the average man, 

 viz, 0.82, but nevertheless are within a reasonable range. The respira- 

 tory quotient of H. R. R. varied considerably in the individual 

 experiments, ranging from 0.76 to 0.93. His average of 0.80 is lower 

 than that for any other subject. Furthermore, it is clear that H. R. R. 



Benedict and Tompkins, Boston Med. and Surg. Journ., 1916, 174, pp. 857, 898, and 939. 



*Harris and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, pp. 42 and 43. Only such of 

 the data for A. J. O. and H. M. S. as were obtained at about the period of this research are used 

 for comparison in this report. (See table 17.) 



