282 THE INCOME OF ENERGY 



excreted in urea, adding 2.5 grams for the nitro- 

 gen of the faeces, sweat, uric acid, etc. 



It will probably be found that the nitrogen 

 excreted equals that ingested (nitrogenous equi- 

 librium). 



Effect of Muscular Exercise on Proteid Metab- 

 olism. On the third day of the preceding ex- 

 periment, the subject should take an unusual 

 amount of measurable exercise. Hill-climbing 

 is a suitable form. The protocol of the experi- 

 ment must contain an approximate estimate of 

 the work done in foot pounds. 



It will be found that muscular work, unless 

 pushed to great fatigue, does not increase pro- 

 teid: metabolism, as measured by the .nitrogen 

 excreted. 



