44 ENERGY TRANSFORMATIONS DURING HORIZONTAL WALKING. 



GENERAL ROUTINE OF THE EXPERIMENTS. 



It will be seen from the foregoing that the experiments irithis research 

 fall naturally into four classes: standing experiments, sitting experi- 

 ments, walking and running experiments, and experiments with food. 

 From the earlier experience of Cathcart with a subject riding a bicycle, 

 it seemed inadvisable to attempt the establishment of a standard lest- 

 ing base-line to be deducted from the total metabolism of the subject 

 while walking. It was therefore decided that each morning, prior to 

 the walking experiment, measurements should be made of the standing 

 resting metabolism; consequently the research included a large number 

 of standing experiments. 



STANDING EXPERIMENTS. 



The respiration apparatus used for this research and previously 

 described was designed more especially for measuring the large amounts 

 of carbon dioxide exhaled during severe muscular exercise, and was, in 

 consequence, fitted with two soda-lime bottles, each of which must be 

 weighed. If only the resting metabolism had been determined, a 

 slightly different arrangement would have been preferred, with the use 

 of but one soda-lime bottle, a spirometer form of apparatus being 

 substituted for the rubber bathing-cap and tension-equalizer. Never- 

 theless, since the resting metabolism with the subject standing was to be 

 used primarily as a base-line to be deducted from the greatly increased 

 metabolism during walking, it was considered that this method of 

 measuring the metabolism during standing would be sufficiently 

 satisfactory for the purpose, and hence the standing metabolism was 

 determined on exactly the same apparatus as that used in the walking 

 experiments. As a matter of fact, the experiments made by Cathcart, 

 and more especially those of Carpenter, 1 have shown that the tension- 

 equalizer form of the unit apparatus gives as accurate measurements of 

 the metabolism during rest as does the spirometer type. In this par- 

 ticular apparatus, however, we could readily have dispensed with the 

 second soda-lime bottle. 



After arriving at the Laboratory, the subject arranged his clothing 

 for an ordinary walking experiment and assumed the standing position 

 on the treadmill, this position being maintained for some time prior to 

 the actual experimentation. After the effect of the slight exertion of 

 coming to the Laboratory and of ascending the stairs had passed away, 

 the mouthpiece was inserted, the noseclip attached, and at the proper 

 time, i. e., at the end of a normal expiration, the 3-way valve connecting 

 the subject with the ventilating system of the respiration apparatus 

 was turned. The experiment was then continued in the usual manner 



Carpenter, Carnegie Inst. Wash. Pub. 216, 1915, pp. Ill to 118. 



