394 EFFICIENCY OF THE ORGANISM 



not all of equal value. In this type of ergometer, where the work 

 to be done can be readily altered by increasing the resistance to 

 be overcome, it is a comparatively simple matter to devise a 

 wide range of experiments in which the effective muscular work 

 can be varied. The only difficulty lies in the selection of the base 

 line. If the work standard be taken as that of the subject sitting 

 on the bicycle performing a definite measured amount of work, 

 in order to find the increased cost in energy caused by the per- 

 formance of this work there may be subtracted : 



(1) The energy expenditure during complete rest the ordinary 

 basal or standard metabolism. 



(2) The energy output when the subject is sitting at rest in 

 the saddle. 



(3) The energy expended when the subject is sitting on the 

 saddle, feet on pedals and his legs are rotated by mechanical 

 means internal or organic work. 



(4) The energy expenditure when the subject is freewheeling, 

 i.e. overcoming the ordinary resistance of the unloaded wheel 

 with most or all of the concomitants of work of this type, sitting 

 posture, internal friction of the legs, extraneous movements asso- 

 ciated with cycle riding, etc. 



(5) The energy expenditure involved in (a) the performance of 

 light work compared with that of hard work or (b) the increased 

 cost of work done at slow and high speeds using the same load 

 in each case. 



When these various base lines are utilised experimentally it is 

 found that there is a steady increase in the degree of efficiency. 

 The average results are as follows : 



TABLE LXXVIII. 



Net efficiency. 

 Average value. 



(f) At rest 



(2) Sitting 



(3) Internal friction 



(4) Free wheel 



(5) Low to high speed 



.21% 

 similar to (f ) 



27% 

 30% 

 30-33 



There is then a variation in the determined efficiency of approxi- 

 mately 10 per cent., and it is a moot question which base line 

 should be selected. Lindhard maintains that the most reliable 

 result is obtained when complete rest or rest in the riding position 

 is adopted as base line, but there is much to be said in favour of 



