FOODS NUTRITION. 



375 



particle? and the amount of the different foods dissolved by the saliva are reported 

 in detail. The author believes that a bite of normal size is sufficiently chewed in 

 half a minute, so that there is a desire to swallow it. In general, vegetable foods 

 were better divided by chewing than animal foods. According to these investiga- 

 tions, the saliva in a very short time (half a minute) dissolved the common starchy 

 food such as macaroni and potatoes. As was to be expected, animal foods, such as 

 egg white and meat, were not dissolved by saliva. The results are discussed at some 

 length. 



The effect of severe and prolonged muscular work on food consumption, 

 digestion, and metabolism, W. (). Atwater and H. C. Sherman { U. ,S. Dept. Agr., 

 Office of Experimoit Stations Bid. 98, pp. 1-56, fig. 1). — A 6-day bicycle race afforded 

 the authors an opportunity to study the food consumption by 3 of the principal con- 

 testants, as well as the digestibility of the food and the metabolism of nitrogen, the 

 investigation being made with the view to determine the effects on these factors of 

 severe and prolonged muscular work. The average amounts of food consumed per 

 man per day follow: 



Average daihj food consumption ofhicycle racers performing severe muscular uvrk. 



Protein. 



Carbo- 

 hydrates. 



Fuel 

 value. 



Nutritive 

 ratio. • 



Miller, during 6-day race 



Pilkington, during 3 days of the 6-day race 



Albert, during 6-day race ! 



Albert, during preliminary period 



Grams. 

 169 

 •211 

 179 

 169 



Grams. 

 181 

 178 

 198 

 153 



Grams. 

 585 

 509 

 859 

 375 



Calories. 

 4,770 

 4,610 

 6,095 

 3,650 



5.9 

 4.3 

 7.3 

 4.2 



The following conclusions were drawn regarding the food consumed, digestibility 

 of the food, and the metabolism of nitrogen: 



"(1) Trained athletes undergoing unusually severe exertion demand a largely 

 increased supply of easily digested food of such kinds as 'agree' with the subject, 

 and that the availability of such food is not greatly affected by the loss of sleep 

 and almost continuous muscular exertion; (2) under such circumstances the metab- 

 olism of nitrogen as well as that of energy is increased, body protein being drawn 

 upon unless the food is very abundant; and (3) trained athletes appear to be able 

 to lose relatively large amounts of body nitrogen without any apparent ill effects. 



"It is conceivable that equally severe and prolonged exertion might jierhaps be 

 undergone without increased metabolism of nitrogen, provided the supply of fuel 

 material was very abundant. This question, however, can be settled only by experi- 

 ments in which the diet is under control." 



The mechanical work and efladency of bicyclers, R. C. Carpenter ( V. S. Dept. 

 Agr., Office of Expjeriment Stations Bid. 98, pp. 57-67 , figs. 2) . — From the data recorded 

 in the investigations noted above, and a number of special determinations, the author 

 discusses the amotuit of work performed by 2 of the bicycle racers, its mechanical 

 equivalent, and the apparent efficiency of the racers. As pointed out, the external 

 resistance may be summarized under 2 general heads — that of the air and that of the 

 bicycle. 



"The total work done by Miller is computed to have been over 15,000,000 foot- 

 pounds, or 7,500 foot -tons, on the first day, and 5,500,000 foot-pounds, or 2,750 foot- 

 tons, on the last day of the race. . . . The average heat equivalent of the work 

 done in the 6 days amounted to 3,102 c-alories. At the same time the food consumed 

 furnished 4,957 calories, making an apparent efficiency of over 60 per cent. ... If 

 we assume that the e(iuivalent exjjosure of the bicycle rider was 4 sq. ft., . . . the 



