116 METABOLISM DURING WALKING. 



of 109 for March 29 and 125 for April 8, no explanation can be found. 

 The readings of the different determinations in each period on both 

 dates are of the same character and it is believed that the blood-pres- 

 sure on these days was approximately as here reported. In any event, 

 all readings are within normal limits for a man of this age (23 years). 



EXPERIMENTS WITH HORIZONTAL WALKING. 

 METABOLISM OF SUBJECTS WHILE WALKING ON A LEVEL. 



After the extensive researches of Durig 1 and his co-workers and the 

 report from this Laboratory on horizontal walking by Benedict and 

 Murschhauser, 2 it would seem but little, if anything, could be added 

 to this subject by multiplying the data. As a matter of fact, to study 

 the influence of grade walking adequately, certain basic data for the 

 individual subjects employed in grade- walking experiments, which 

 pertain to their metabolism while they were walking on a level, are 

 essential for the computation of the horizontal component in the analy- 

 sis of the grade-walking experiments. Accordingly, horizontal-walk- 

 ing experiments were made with each of our subjects; in some instances 

 the series extended over a considerable period of time. 



Durig and his associates found that on the average the energy re- 

 quired with rates of walking below 80 meters per minute corresponded 

 approximately to 0.55 gram-calorie for each horizontal kilogrammeter. 

 Since there were rather considerable differences in the rates of walking 

 in this present series of tests, the rate exceeding at times the normal 

 average walking speed, it is obvious that grand averages would have 

 little value for general comparison, and fundamental data for walking 

 at the several speeds is essential for each series of grade-walking tests. 

 Usually, however, the rates of walking ranged from 50 to 80 meters 

 per minute, i. e., those normally used by an individual in "taking a 

 walk/' and a general picture of the results is thus worthy of short con- 

 sideration ; consequently, we shall first discuss the values without noting 

 particularly the effect of change in the rate of walking. 



TOTAL METABOLISM DURING HORIZONTAL WALKING. 



The individual data for each subject are given in tables 8 to 12. 

 The average results are also given for all the subjects in table 28, 

 these being based primarily upon gross changes in the speed of walk- 

 ing, expressed in 5-meter intervals. The following notes and comments 

 are to be looked upon primarily as supplementing the original data 

 and in the nature of discussion of certain of the results. Stress is laid, 

 however, only upon general figures, which take little, if any, account 

 of differences in the rate of walking. 



With H. R. R., six horizontal- walking experiments were made, with 



rig, Denkschr. d. math.-natur. Klasse d. kaiserl. Akad. d. Wissensch., 1909, 85, p. 263. 

 'Benedict and Murschhauser, Carnegie Inst. Wash. Pub. No. 231, 1915. 



