How much carbohydrate should be consumed during exercise to improve endurance performance. The basic question was answered by researchers decades ago. Carbohydrate consumption enhances endurance performance. Subsequent research has better defined the relationship between consumption and performance. For example short acting high glycemic carbohydrate has a greater positive effect than longer acting carbohydrates. We also know that the addition of protein in a 4-1 ratio improves endurance performance and post exercise recovery.
The question that still remains is how much carbohydrate should actually be consumed. Too little and there is marginal impact on performance; too much and G.I. problems will occur. A recent study by British researchers may answer the question. The study evaluated four levels of carbohydrate ingestion on endurance performance, 0, 20, 39 or 64 grams per hour. As shown in the figure below 20 grams/hour provided a small improvement in endurance; 40 grams per hour provided a significant boost- 6.1%. Increasing the carbohydrate to 64 grams/hour did not significantly improve endurance further. Thus the ideal carbohydrate consumption rate during exercise is 40 grams/hour.
The study also analyzed other metabolic data which will be which is certainly of interest to the endurance athlete and will be reviewed in future in Performance Nutrition Tips.