STUDY OF THE EFFECT OF DIETARY FACTORS AND VARIOUS EXERCISES ON THE SWIMMING PERFORMANCE OF THE ALBINO-RAT

In experiment 1 a double-phase test diet (high-protein low-carbohydrate phase [HP], 5 days and high-carbohydrate phase [HC], 2 days] was compared to a normal diet by measuring performance in rats trained by steady or interval swimming exercise. The tests performed on the 8th day showed the swimming performance to be improved to a similar extent by the 2 training procedures which was further improved by the test diet in the exercised animals. Changes in liver glycogen, blood glucose and serum corticosterone reflected the influence of exercise which in some cases was potentiated by the test diet. In experiment 2 the 5 days of high protein intake were treated separately from the effect of the double-phase test diet as a whole to study the mechanism. The animals were exercised by treadmill running of 7 days. Cytochrome P450 content of the liver rose under the effect of exercise as well as the HP phase supplying additional evidence for the enzyme inducer effect of physical exertion. Glycogen decreased in the muscle and liver during the HP phase and returned to normal after the HC phase. Liver glycogen rose to a higher level than normal in the trained groups but muscle glycogen values remained lower; this may be related to the shortness of training and to an accelerated rate of turnover. High protein intake associated with a depletion of carbohydrate stores, when followed by replenishment of caloric reserves, might be advantageous in improving physical performance.