PLAN OF KESEAKCH. 43 



walking, the subject being required on several days to walk for a con- 

 siderable length of time. 



While, in common with several other investigators, we have believed 

 that the most sharply defined results can be obtained in experiments 

 without food, nevertheless the experimental conditions were such as to 

 make it relatively simple for us to obtain values after the ingestion of 

 food. With this end in view, we made specific studies of the metabo- 

 lism under the various conditions of standing, walking at various 

 speeds, running, and after fatigue, not only when the subject was with- 

 out food in the stomach but also after food had been taken. The 

 experiments carried out after food duplicated the experiments with the 

 subject in the post-absorptive condition; it was therefore possible to 

 note whether or not there was a summation effect on the metabolism 

 due to the ingestion of food and to the work. 



While in some of the experiments the diet was uncontrolled, in a 

 number of them it was prescribed. The constituents of the meal 

 varied widely in these latter experiments, a special protein diet being 

 supplied on some days, on others a diet containing an excess of fat, and 

 again a diet with a large proportion of carbohydrate. The results 

 of these experiments accordingly gave data as to the effect of a special 

 diet upon the metabolism during walking. 



This, in brief, was our plan of research at the beginning of the series 

 of observations. Incidentally a number of other important physio- 

 logical details were developed as the research progressed. These will 

 be taken up specifically in the discussion of the results of the experi- 

 ments. 



