The differences between glucose and sucrose were investigated on their effects of the recovery process after exercise. After 17 hours fasting, male rats weighted 100-150g were forced to swim for three hours in 30°C warm water. Twenty percent solution of glucose or sucrose were administered orally by a stomach tube after the exercise. Results were as follows; 1) Low blood sugar levels caused by severe exercise were reduced by administration of sugar and hyperglycemia continued more than three hours, while the maximum blood sugar level in non-exercised group was shown at one hour after administration and it decreased to normal value by three hours. 2) Although there was very slight sugar left in digestive tract (stomach to ileum) at one hour after glucose administration, delaying of sugar absorption was remarkable in sucrose administered groups ; that is, 125.2 mg% and 20.9 mg% of sugar were measured at one and three hours, respectively, after giving of sucrose. 3) Glycogen contents in liver and muscle increased more than that before the exercise in glucose administered groups by three hours after swimming. The recovery was not remarkable in sucrose administered rats, especially in liver. 4) Total protein concentrations in serum were kept almost the same in all groups. Transaminase activities (GOT & GPT) in serum were increased slightly after exercise, however, lactic dehydrogenase activities were decreased. No special changes in enzyme acitvity of serum were found amoung the experimental groups treated with sugars.
To reveal the limiting factors in endurance running on the treadmill was the main interest in this study. An excellent Japanese long distance runner who later got the third place at the Olympic marathon race in 1964, K. Tsuburaya, 23 served as the subject. The all-out running time, heart rate, respiratory rate, pulmonary ventilation and oxygen intake were measured when he ran at the two different speeds, 260m/min. and 240m/min., on the treadmill with 8.6% slope. From these measurements tidal volume, oxygen removal and oxygen pulse were calculated. The all-out running time of this subject was found to be 6 minutes 58 seconds at the speed of 260m/min. and 21 minutes 09 seconds at the speed of 240m/min.. The heart rate and respiratory rate were increased during running toward the point of “all-out”. It is worthy to note that the respiratory rate showed an abrupt increase near the point of exhaustion accompanied by decrease of tidal volume. The oxygen removal, the raito of oxygen intake to pulmonary ventilation, was also decreased gradually during running until it decreased to about 35 near the point of “all-out”. It was supposed from these results that the decrease of efficiency of respiratory function might play a big role to limit the endurance for running. It should be, in the next step, decided whether this decay of efficiency of the respiration would be caused by decreased cardiac output or uneven distribution of gas in the lung.