The Nutritional Function of Carbohydrates for the Endurance Athlete

Proper nutrition for the endurance athlete has been studied and debated amongst scientists and nutritionists in an attempt to develop an optimum system of dietary measures that can be taken to develop an increase in performance for the endurance athlete. This paper will discuss the major role in which carbohydrates provide energy for the endurance athlete, important dietary considerations of the endurance athlete, and what/how/when to eat to enhance endurance sports performance.

Major role of carbohydrates to provide energy for the endurance athlete

“Till the late 1800s it was believed that protein was the most important source of energy for muscle. In the early 1900s it was discovered that not protein but carbohydrate was an important fuel for exercise” (Jeukendrup, A. 2013). While recommendations are not always very specific, new research and understanding of the science behind the use of carbohydrates during exercise has provided changing and evolving guidelines towards the feeding of carbohydrates during exercise. “With the evidence from studies and new insights obtained in the last 5-10 years it is possible to provide much more prescriptive and precise advice to athletes.” (Jeukendrup, A. 2013).

Important dietary considerations of the endurance athlete

Important dietary consideration to carefully consider when instituting a programming regime for an endurance athlete is to take into account the type of exercise being performed by the endurance athlete. “With carbohydrate feeding during cycling it has repeatedly been shown that muscle glycogen breakdown is unaffected. During running, however, there are suggestions that muscle glycogen breakdown is reduced in particular in type I muscle fibers.” (Jeukendrup, A. 2013).

Endurance athletes also tend to continuously perform their exercise (hence the name endurance) whereas traditional team sports have high intensity exercise for a short period of time that is followed by another short period of time with relatively low level of exertion. Creating a dietary program for an endurance athlete to follow should carry significant changes in feeding as would the feeding schedule to be used for a team sport athlete. The tempo in which an athlete carries out their chosen exercise determines the level of feeding needed. The intensity used to perform an exercise determines the rate in which the carbohydrates are used. An example of this is seen when comparing a sprinting athlete as compared to a distance (endurance) runner. Sprinting utilizes rapid muscular movements and require the body to use a high rate of performance power. An endurance runner will utilize this same rate of performance power over the distance of their run.

What to eat, how much to eat, and when to eat to enhance endurance sports performance

“In general during exercise longer than 2 hours, carbohydrate feeding will prevent hypoglycemia, will maintain high rates of carbohydrate oxidation and increase endurance capacity compared with placebo ingestion.” (Jeukendrup, A. 2013). Energy is required to perform exercise, and for the endurance athlete, the need to generate ATP over the course of training requires the athlete to carry the capacity to generate ATP over the duration of the exercise. Below is a sample example of the nutritional training recommended for the various intervals of training.

• 30-75 minutes; small amounts or a mouth rinse of single or multiple transportable carbohydrates. Nutritional training highly recommended.
• 2 hour duration; 30g/h; single or multiple transportable carbohydrates. Nutritional training recommended.
• 3 hour duration; 60g/h; single or transportable carbohydrates. Nutritional training highly recommended.
• >2.5 hour duration; 90g/h; glucose:fructose only. Nutritional training essential.

In conclusion, the endurance athlete has been scientifically shown to utilize carbohydrates and ATP at a slower rate than can be seen within the team sport and high intensity sport realm. Careful consideration must be used to adequately program feeding for the endurance athlete to ensure the athlete is receiving their nutrition over time, as they utilize their energy far differently than the team sport athlete.