Influence of Glycemic Index-Based Menu on Endurance Performance of Athletes

Abstract

Carbohydrate plays an important role in physical activity including in sports. However, consuming high carbohydrates before exercises can cause metabolic effects, i.e. unfavorable hyperglycemia and hyperinsulinemia in endurance performance before training. This research is aimed at knowing the influence of meal consumption with different glycemic indexes (GI) on the endurance performance of athletes involving in 5-km run. This research uses controlled random experimental design. The subjects taking part in this research are 15 athletes, consisting of 8 persons in low-GI group and 7 persons in high-GI group. After overnight fasting, the subjects consume the intervening meals in accordance with their groups (low GI or high GI) three hours before 5-km run. The intervening meals contain 1000 calories with glycemic indexes of 37 and 85. The average age of the subjects is 19.0  0.8 years, while the average body weight, body height, and body fat percentage is 56.2  8.9 kg, 163.8  6.8 cm and 17.78  4.50%, respectively. The average hemoglobin, hemotocrite, and VO 2max of the subjects is 16.24  1.54 mg/dl, 43.61  2.81% and 44.99  6.00 ml/kg BB/minutes, respectively. The research findings show that, before and after interventions, the average finish times in 5-km running in the subjects with low-GI group are 23.85  1.64 minutes and 23.91  1.46 minutes faster than those with high-GI group (27.51  2.21 and 26.95  3.11 minutes). This study concludes that there is an influence of meal consumption with different GIs to performance of endurance in 5-km run among college athletes (p<0.05).