What is reactive hypoglycemia in sport?

The reactive hypoglycemia happens by the rapid elevation of blood glucose due to in high concentrations, immediately before starting the exercise. muscle contraction together with the mobilization of muscle glycogen stores causes the glucose circulating in the blood to be rapidly captured.

What is the glycemic index?

The GI or Glycemic Index is a value used to measure how quickly a food can raise glucose, that is, the blood sugar level (the index can be high, medium or low):

• The values over 70 are considered a glycemic index high.
• Between 69-55 are considered glycemic index medium.
• Less than 54 is considered glycemic index under.

Gels, gummies, some sports bars, honey ... are examples of high GI foods. If we take foods or supplements with a high glycemic index, just before the competition, such as a gel, insulin release is stimulated, the combined action of insulin and that of the practice of exercise causes a marked decrease in blood glucose (blood glucose). So a reactive hypoglycemia.

Cases in which blood glucose may increase

Taking a gel before the competition will not necessarily produce reactive blood glucose. There are different situations in which to take a sports gel it can be beneficial and others where it is not. In fact, not all sports gels or supplements are the same. The absorption will vary greatly depending on the sugars that they have as ingredients. If the sugars are rapid absorption, that is to say that their ingredients contain glucose, sucrose, dextrose ... or if they are slow absorption (fructose, palatinose ...) hypoglycemia may or may not occur, since glucose has a GI of 100 and fructose has a GI of 20, the difference is more than remarkable.

Let's see Two examples clear and differentiated:

• Case 1: athlete who, before the sports event, has followed a correct eating strategy, with an adequate carbohydrate overload, so that their glycogen stores are full. If you take a gel five minutes before the test, you may have reactive hypoglycemia, therefore it is not necessary at that time.
• Case 2: athlete who has not adequately performed the overloading eating strategy, so his glycogen stores are not full. In addition, it has been intensely warmed up 15 minutes before the test. In this situation take a gel five minutes before the test would be justified, by not having carried out a glucose overload, and having spent 20 minutes intensely heating the blood glucose is already being used as a substrate, so ingesting a gel at that moment would provide more substrate. Insulin, having started physical activity, decreases, so glucose uptake will not be abrupt and reactive hypoglycemia should not appear.

As a general rule, the more different sugars the gel or supplement has, the better, since the absorption rate improves as the transporters of these sugars are not saturated. However, each person is different, and although there are common tips, certain people are more prone to hypoglycemia reactive than others. The genetic factor also influences, so comparing athletes does not always work.

Five tips to avoid hypoglycemia

In conclusion, reactive hypoglycemia it's easy to avoid If the situation and the way to act are known, we can do it by following some tips:

Monica Carreira Diploma in Human Nutrition and Dietetics Sports nutrition specialist

• In the case of take carbohydrates between an hour and a half and three hours Before the test it is recommended that they be more than 60 gramsSince it has been observed that more hypoglycemia occurs if less than 25 grams are taken than if more than 60 grams are taken. Always medium or low GI.
• Not taking high GI foods or supplements just before the competition, if they are taken, as long as an intense warm-up has been started previously.
• It is preferable to choose supplements with different types of sugars for a more gradual absorption.
• If you have any questions, it is always recommended Consult with a .
  • Reactive hypoglycemia happens by the rapid elevation of blood glucose (due to the intake of high concentrations of sugar), immediately before starting the exercise.
  • Not all gels or other sports supplements They are the same, since the absorption will depend a lot on the sugars that they have as ingredients.
  • Each person is different, and although there are common tips, certain people are more prone to reactive hypoglycemia than others, the genetic factor also influences.
  • Remember that the