Both high and low glycemic index (GI) foods have a place in the diet of athletes.
What is GI?
GI is an index which measures post-prandial blood glucose response to carbohydrate containing food. Foods with a GI in the higher range will cause a more rapid delivery of the carbohydrate into the bloodstream, and foods with a GI in the lower range, will provide a slower more sustained release of glucose. The GI of a particular food is dependant on a variety of factors, the type of starch as well as the content of fiber, fat and protein in the food.
Low GI Carbohydrates
The best strategy for athletes is to utilize low GI carbohydrates for pre-exercise to allow for sustained energy, and high GI for post-exercise to enhance recovery with quick glycogen uptake in the muscles. However the benefits of using of low GI carbohydrates pre-exercise is questionable if the athlete is able to fuel up during the session, which prolongs energy levels and can also enhance performance.
High GI Carbohydrates
High GI carbohydrates are most effective when an athlete has multiple training sessions in one day or a session that is less than 8 hours away. Total quantity of carbohydrates becomes more important if the next training session is more than eight hours away, as the body has adequate time to recover over a longer time period, allowing for sufficient carbohydrate consumption.