24-HOUR ENERGY REQUIREMENTS. 



211 



were inside a respiration chamber with the activity considerably 

 restricted. 



TABLE 38. Twenty-four hour energy requirements of boys. 



Thus far we have been able to consider children at two distinct levels 

 of activity: (1) basal, i. e., with complete muscular repose; (2) with 

 activity restricted by the confines of a respiration chamber. With 

 most children many hours in the day are spent in the school-room. 

 The classic research of Sonden and Tigerstedt has supplied us with 

 information as to the energy requirements of children under these 

 conditions of modern activity; their computations were made by Carl 

 Tigerstedt 1 on the basis of calories per kilogram of body-weight, 

 assuming that 1 gram of carbon dioxide corresponds to 3 calories. 

 Although these values are in no sense basal, they represent data 

 obtained with an approximately uniform muscular activity for the 

 various ages. The results for the age-period within the range of our 

 study are given in table 39, and show clearly a decrease in metabolism 

 per kilogram of body-weight from 7.9 years to 15.5 years of age. The 

 values all lie considerably higher than not only the basal, but also the 

 values for 24-hour chamber experiments given in table 38, thus showing 

 on the whole a somewhat greater degree of activity for the school 

 children. These latter values more nearly approximate the true 24- 



TABLE 39. Twenty-four hour energy requirements of children (Sonden and Tigerstedt). 



Tigerstedt, Carl, loc. cit. 



