155-o : CARBOHYDRATES DURING EXERCISE

BACKGROUND

Carbohydrates and fats are the most important energy sources during an endurance exercise. The body stores carbohydrates in the form of glycogen in the muscles and this stock is addressed when an athlete should make an endurance effort. However, the storage capacity of the body for carbohydrates is not infinite. If an athlete, with a well-replenished glycogen stock, intensively exerts an hour and a half, this stock will be empty. When glycogen is depleted, performance will noticeably deteriorate. An athlete can avoid this by eating or drinking  carbohydrates during exercise.

PERFORMANCE
ENDURANCE PERFORMANCE   <60 minutes

For an athlete who must do an endurance performance of about one hour intake of  carbohydrate has  no use during exercise. It is of course important that the glycogen stores  are well stocked  at the start.

ENDURANCE PERFORMANCE   1-2 hours

If the effort will take more than an hour the body is doing an earnest appeal to the glycogen stores. Depletion of this stock will undoubtedly lead to performance degradation. If an athlete ingests in two hours about 30 grams of carbohydrate per hour, the performance will improve nearly five percent on average compared with the non-intake of carbohydrates.

ENDURANCE PERFORMANCE 2-3 hours

At a time intensive effort of more than two hours, glycogen is depleted and will drastically deteriorate performance if an athlete does not take carbohydrates during exercise. If an athlete ingests up to 60 grams of carbohydrates per hour performance will be at least six percent better compared to the non carbohydrate intake.

ENDURANCE PERFORMANCE > 2½ hours

For a very long endurance performance an athlete will have to take 90 grams of carbohydrates per hour to reduce deterioration in performance as much as possible.

HOW TO USE
ENDURANCE PERFORMANCE  1-2 hours

An athlete can take 30 grams of carbohydrates per hour through drinks or gels. Of course, it is also possible to ingest carbohydrates via solid food, but liquid is preferred because the body can absorb liquid carbs faster. Most types of carbohydrates are suitable for this purpose.

ENDURANCE PERFORMANCE 2-3 hours

For athletes it is the best to take 60 grams of carbohydrates  by a drink. It is important that an athlete tries out the intake of these amounts of carbohydrates first in training situations as this can cause stomach and intestinal complaints.

ENDURANCE PERFORMANCE > 2½ hours

If an athlete wants to take 90 grams of carbohydrates per hour it is necessary that he eats a combination of different types of carbohydrates. The body cannot absorb infinitely more carbohydrates of one kind. A combination of glucose and fructose or maltodextrins and fructose for example, can ensure that the body can take up more grams of carbohydrate per hour. The ratio in the beverage or gel must be in these examples, 2: 1 (glucose / maltodextrins : fructose).
Again, it is important that an athlete first tries out these large amounts of carbohydrates in workouts.

CONCLUSION

The longer the exercise, the greater the intake of carbohydrates. This is not surprising since glycogen is depleted at a given moment, causing a  reducing performance. It is quite clear that an athlete should take carbohydrates during intense efforts lasting more than an hour.