Carbohydrate Ingestion Before Exercise

A high-carbohydrate meal that is completed approximately 90 minutes before physical activity has been shown to improve endurance performance. After this preexercise meal, athletes should consume carbohydrates right up to the beginning of the training session or competition to avoid low blood glucose. Two strategies can be followed:

1. Ingestion of a carbohydrate-containing sports beverage using a sipping strategy, where approximately 2 to 4 ounces (60 to 120 milliliters) of beverage is consumed every 10 to 15 minutes.
2. Snacking on low-fiber, starchy foods (such as saltine crackers) every 15 minutes, washed down with ample quantities of water.

Athletes should avoid eating patterns that could stimulate a reactive hypoglycemia, which is caused by ingestion of large quantities of foods with a high glycemic index, but should also avoid the hypoglycemia that could occur from consuming no carbohydrates or from delayed eating. Snacking and sipping procedures appear to be well tolerated and help maintain blood glucose.