For each trail, a rest period of 25 min was maintained to get rid of the earlier test effect of fatigue. The experiment was conducted with each diet per day, noting the time levels for each shuttle run of subjects with the help of a stopwatch. The fatigue indices were calculated and rated on a 5 unit scale for easy comparison at minimum values. The test results were was coded on to the computer to do a variance analysis. A Two-way analysis with repetitive data was conducted and found the Plt.0.05 indicating that the diet has a significant effect on the endurance levels of the runners. The study found that food with High Carbohydrates with Low Glycemic Index levels shows higher fatigue levels in shuttle runners than other levels of food. The graphical representation of summary averages confirm that there is an interaction between the diet levels and the subject’s performance levels, and also confirms the High Carbohydrates with Low Glycemic Index level food as the highest performance level The purpose of this particular study is to examine the effect of low, medium and high carbohydrate diets with low and high glycemic index ratings on the rate of fatigue. Fatigue- acute impairment of exercise performance that includes both an increase in the perceived effort necessary to exert a desired force or power output and the eventual ability to produce that force or power output. ( Davies and Bailey, 1996) Carbohydrate is considered an important source of energy or fuel for the body. Apart from carbohydrates, there are other essential nutrients necessary for the functioning of the body. From the point of view of athletes in competitive sports, individuals performing regular work out sessions, both of high intensity and high endurance types, of either prolonged and short duration, the kind of carbohydrates ingested.