92 METABOLISM DURING WALKING. 



had a measurably higher pulse than any of the other men, a point 

 which should be borne in mind in the later consideration of the results 

 of the walking experiments. 



The heat-output per 24 hours per kilogram of body-weight, in which 

 an effort is made to equalize differences in body-weight, shows a range 

 of 22.9 to 26.7 calories. This compares favorably with the 25.7 calories 

 per kilogram of body- weight given by Harris and Benedict as an average 

 value for 136 men. 1 The heat produced per square meter of body- 

 surface, with the body-surface computed by the height-weight chart of 

 the Du Boises, shows variations of considerable magnitude, ranging 

 from 776 calories with H. M. S. to 964 calories with H. R. R., with an 

 average of 893 calories. The average value given by Harris and Bene- 

 dict for the 136 men previously referred to was 925 calories per square 

 meter of body-surface. It is of considerable importance to note that 

 with the group of men selected for use in treadmill experiments, and 

 presumably in normal health, such wide variations appear in the heat- 

 production per square meter of body-surface. 



The difficulty in predicting the heat-production of an individual from 

 either the surface area or the body- weight alone is clear from the values 

 given in table 17. A further indication of the normality of our 

 subjects may be found in a comparison of these basal measurements 

 with values computed by means of the prediction formula of Harris and 

 Benedict, 2 which is based upon the biometric analysis of values obtained 

 for 136 normal men. This comparison is made in table 18. 3 With 

 every individual the predicted heat-production is reasonably close to 

 that determined, the widest deviation being with H. M. S., whose basal 

 metabolism was 91 calories per 24 hours less than the predicted 

 metabolism, or a difference of 6.2 per cent. 



It should be brought out here that we are not dealing with a group of 

 men of a pronouncedly athletic temperament. The only man who 

 could logically be classed as an athlete was A. J. 0., who was a semi- 

 professional baseball player. 4 In an earlier study, in which the meta- 

 bolism of athletes and normal individuals was compared, 5 the evidence 

 was reasonably clear that athletes as a group show a higher metabolism 

 than do normal individuals, although the original estimate of the 

 influence of athletic build and habit upon the metabolism was somewhat 

 reduced by a subsequent careful biometric analysis. 6 From the values 

 given in table 18, it is evident that the agreement between the predicted 

 and the determined heat-output is close enough to preclude the COn- 



and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, p. 204. 



2 Harris and Benedict, Ibid., p. 227. 



3 It should he stated that the subjects of this study on the effect of walking were, most of them, 

 used for obtaining the data employed by Harris and Benedict. In other words, the predicted 

 values given in table 18 are not independent of the derivation of the formula, but were a part of 

 the results obtained for the group of 136 men from which the formula was computed. 



4 This subject vas used by Benedict and Murschhauser (Carnegie Inst. Wash. Pub. No. 231, 

 1915), who report other data concerning him. 



8 Benedict and Smith, Journ. Biol. Chem., 1915, 20, p. 342. 



Harris and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, p. 245. 



