The glycemic index (GI) influences meal planning for athletes by categorizing foods based on their impact on blood sugar levels. Foods with a high GI result in rapid spikes in blood sugar, providing quick energy for intense workouts. In contrast, low GI foods promote steady energy release, ideal for endurance activities. Athletes can use GI to strategically plan meals and snacks, optimizing performance and recovery. A balanced approach to GI helps maintain energy levels, improve exercise outcomes, and prevent fatigue during training sessions.