title: A study of the effect of dietary factors and various exercises on the swimming performance of the albino rat.
abstract: In Experiment 1 a double-phase test diet (high-protein low-carbohydrate phase (HP): 5 days, high-carbohydrate phase (HC): 2 days) was compared to a normal diet by measuring all-out performance in rats trained by steady or interval swimming exercise. The tests carried out on the 8th day showed the swimming performance to be improved to a similar extent by the two training procedures, to be further improved by the test diet in the exercised animals; changes in liver glycogen, blood glucose and serum corticosterone reflected especially in 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 in order to study the mechanism. These aminals 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, thus supplying additional evidence for the enzyme inducer effect of physical exertion. Glycogen decreased both in the muscle and liver during the HP phase and returned to normal after the HC phase. Liver glycogen rose to an even 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 was found to have an effect of its own which, when followed by replenishment of calories reserves, might be used to advantage in improving physical performance.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D006003:Glycogen / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D010805:Physical Conditioning, Animal; D010807:Physical Endurance; D051381:Rats; D013550:Swimming
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D008112:Liver Glycogen; D006003:Glycogen; D003577:Cytochrome P-450 Enzyme System; D003345:Corticosterone