The purpose of the study was to find an effect of high fat diets on the running endurance and serum lipids and proteins of Sprague-Dawley 48 male rats. The supply them with 40.45 percent of the total energy intake from fat, the experimental diets were supplemented with lard, soybean oil and lard mixed soybean oil to basic diet respectively. To observe the changes of the endurance and the concentrations of serum lipids and proteins, the experimental animals were taken a daily exercise in tread mill for 3 weeks until they were too tired to do more.
The results were as follows.
1. High fat diet groups (C,D,E,F,G and H groups) show a more remarkable increase significantly running endurance from the 1st to the 6th day, as compared with the basic diet group (B).
2. The basic diet group (B) discloses high running endurance, while the other groups rather a decrease of the endurance.
3. Both C and G groups of all high fat diet groups give from the 16th to 19th day a sure sign of continuous increase of running endurance.
4. The concentration of serum total lipid slightly increased in the groups of high fat diets, but serum cholesterol decreased significantly.
5. The concentration of serum neutral fat and phospholipid increased slightly or significantly in high fat diet groups but the neutral fat content decreased significantly in the basic diet group.
6. HDL concentration increased significantly in high fat diet groups but LDL and VLDL decreased significantly.
7. The content of serum total protein increased greatly in high fat diet groups except E group, and GOT, GPT and LDH contents decreased.
8. The concentration of serum glucose decreased in high fat diet groups as compared with basic diet group.
The findings aforementioned reveal the running endurance presents a significant increase at the initial stage of high fat intake, not varying with the saturated or unsaturated fatty acid. The results of serum analysis manifest that the diet group of soybean oil contained much unsaturated fatty acid shows a more decrease of the serum total cholesterol, free cholesterol, total lipid as compared with the lard diet group. I think that can be recommended to use high unsaturated fatty acid to improve running endurance.