140 METABOLISM DURING WALKING. 



meter ranging between 0.512 gram-calorie on February 25 and 0.637 

 gram-calorie on April 5. The average increment on this basis for the 

 7 days was 0.579 gram-calorie. The daily average increase per hori- 

 zontal kilogrammeter shows, if anything, a tendency to increase on the 

 last 2 days, when the walking was done at a somewhat slower speed. 

 The energy cost for consecutive periods shows no trend in any one 

 direction. It can hardly be said that the subject walked regularly 

 enough to develop any training effect, though it is to be assumed that 

 acquaintance with the routine might have reduced any psychical effect 

 or feeling of novelty. 



Of the 15 days during which W. K. walked on a level (see table 31), 

 13 days were in March, at the beginning of his use as a subject. Since 

 there were no extreme differences in the speed of walking, the range 

 being from 58 to 68 meters per minute on these days, they offer a 

 fairly consecutive record from which comparisons may be expected. 

 Tha range in the daily cost per horizontal kilogrammeter during March 

 is from 0.574 gram-calorie on March 4 to 0.440 gram-calorie on March 

 31. (See table 31.) This decrease in the cost might be taken to indi- 

 cate an improvement but for the fact that the change is very irregular, 

 although as a rule the higher values are found in the first days of the 

 month. Thus, the average for the first 7 days of experimenting in 

 March is 0.516 gram-calorie and for the last 6 days it is 0.480 gram- 

 calorie per horizontal kilogrammeter. It should also be noted that 

 the last day on which W. K. was a subject (June 23), after 4 months of 

 almost daily walking (see also table 15), his average cost per horizontal 

 kilogrammeter was lower than that on any other day, namely, 0.409 

 gram-calorie. The results of the series might be taken to indicate, 

 on the whole, a decrease in the cost per horizontal kilogrammeter as 

 this man continued his experiments. The average for the entire series 

 of horizontal walking experiments with W. K. shows an expenditure 

 over that for standing of 0.490 gram-calorie per horizontal kilogram- 

 meter. 



In the case of E. D. B. the energy cost per horizontal kilogrammeter 

 ranged from 0.603 gram-calorie on October 9, the first day of his walk- 

 ing, to as low as 0.407 gram-calorie on November 24, while the average 

 for the total 61 days is 0.478 gram-calorie. (See table 32.) To 

 study the effect of training, the values for the same speeds have been 

 grouped chronologically in table 34, so that the results for the different 

 days will be comparable. The daily averages for both the total heat- 

 output and the increment per horizontal kilogrammeter are given in 

 this table. For the approximate speed of 55 meters per minute, the 

 speed at which E. D. B. first walked, the cost per horizontal kilogram- 

 meter fell quite consistently from 0.603 gram-calorie on October 9 

 to 0.407 gram-calorie on November 24. For a speed of 65 meters per 

 minute there is also a fall between October 16 and December 13, 



