Before dealing with the topic, we briefly summarize the main functions of this hormone, extensively covered in the article "Insulin and physiology". Thanks to its action, insulin:
facilitates the passage of glucose from the blood to the cells and therefore has a hypoglycemic action (lowers blood sugar)
facilitates the passage of amino acids from the blood to the cells
it has an anabolic function because it stimulates protein synthesis
facilitates the passage of fatty acids from the blood to the cells
stimulates the synthesis of fatty acids and inhibits lipolysis
Many of the diets born in recent years have set themselves the goal of controlling insulin secretion thanks to correct food combinations. An "overproduction of this hormone" following the consumption of large quantities of carbohydrates can in fact lead, in the long run, to develop pathologies such as obesity and diabetes (to deepen the topic and find out why it is so important to keep blood sugar constant, I refer you to the article: Blood sugar and weight loss).
All this alarmism towards insulin has also reached the ears of athletes, generating in some cases unnecessary worries. First of all, remember that it is not the insulin itself that is dangerous but the incorrect habits that amplify the so-called "negative" effects. .
Therefore it is not only what we eat that is important but also what we do during the day. In particular, the body of a sportsman is able to better modulate the insulin action defending itself from possible negative effects. But let's get to the first fundamental point:
it is not true that insulin makes you fat
or rather it does so only when the following conditions occur simultaneously:
- the muscle and liver glycogen stores are saturated
- a surplus of carbohydrates (including complex ones) is taken from the diet by not taking in adequate quantities of the other nutrients (fats and proteins)
-after this intake, sedentary activities take place which prevent the use of excess blood glucose.
If it is true that such conditions frequently occur in sedentary people who eat poorly, it is also true that it is also true that a sportsman will hardly find himself in all three situations at the same time:
the action of insulin is useful for sportsmen
in particular at the end of physical activity to supply the body with carbohydrates spent during physical exercise. The post-workout meal must in fact provide the right amount of simple sugars in order to activate an insulin peak that restores glycogen stores.
Remember that for the same amount of oxygen consumed, carbohydrates have a higher energy yield than fats. Therefore, the greater the glycogen stores, the better the performance of an athlete engaged in endurance races (marathon, long distance race, etc.).
A separate discussion should be made for body building and power activities
During these activities the body consumes limited quantities of carbohydrates. It follows that a body builder can find himself more easily in the three conditions described above.
However, even the athletes of these disciplines can benefit from the insulin action. We remember that insulin is the anabolic hormone par excellence and that, in addition to facilitating the entry of fats and carbohydrates into the cell, it also facilitates the "entry of proteins.
This explains why after weight training it is advisable to consume carbohydrates with a high glycemic index (for example a banana) together with whey proteins. This association causes an insulin spike that favors the entry of amino acids into the muscle cells, where they will come. used to repair damaged protein structures and promote anabolism.