42 ENERGY TRANSFORMATIONS DURING HORIZONTAL WALKING. 



PLAN OF RESEARCH. 



While this investigation was undertaken primarily with the object of 

 studying the metabolism of walking on a level, certain preliminary 

 observations were necessary, particularly for the purpose of establishing 

 a base-line for comparison with the metabolism during walking. As 

 has previously been stated, certain investigators, in studying the 

 metabolism during walking, have been inclined to employ as a basis 

 of comparison the metabolism determined with the subject in the lying 

 position and without food in the stomach, i. e., maintenance metabo- 

 lism. Many attempts have also been made to study the metabolism 

 with the subject in the standing or the sitting position, these values 

 being deducted from the total metabolism obtained with the subject 

 walking, the increment being considered as due to the work of forward 

 progression. It was therefore necessary in our research to study the 

 metabolism not only during walking but also under other conditions, 

 thus increasing the number of problems to be studied. 



A considerable number of experiments were carried out with the 

 subject standing in different positions, those used being (1) with the 

 subject standing with the body relaxed, as one would stand quietly 

 without external support; (2) leaning against a support at the back; 

 (3) leaning upon a staff; and (4) standing with muscles tense in the 

 position of "attention." By determining the metabolism in these 

 various resting or standing attitudes, all conceivable base-lines could 

 be obtained. Furthermore, it was found that during experiments with 

 rapid walking there was considerable lateral motion of the arms, as is 

 the habit with many walkers, particularly professional pedestrians. 

 Consequently certain experiments were made with the subject standing 

 and swinging the arms from side to side as in a fast walk, but without 

 moving the feet. A number of observations were also made of the 

 metabolism with the subject sitting, with the idea that the values thus 

 obtained might be used for the basal metabolism. As a matter of 

 fact, only a few of the sitting experiments were made with the subject 

 in the post-absorptive condition and the values secured have not been 

 used for actual comparison purposes. 



The main object of the research was, of course, the study of the 

 metabolism during walking and specifically the study of the increase 

 in the metabolism due to walking at increasing speeds. In the series 

 of walking experiments, therefore, the subject was required to walk at 

 a very slow speed, then at a medium speed, and finally at a very fast 

 speed. In a few experiments the subject actually ran, thus giving data 

 for comparing the work of forward progression while the subject was 

 walking with that while he was running, two entirely distinct methods 

 of forward progression. Certain observations were also made regard- 

 ing the effect upon the metabolism of fatigue due to long-continued 



