Fasting on an empty stomach. How does it affect my body?

He fasting training It is one of the great themes discussed in sports nutrition. We are going to try to focus this article on what happens physiologically in our body, and assess what happens according to what sport or if you suffer from pathologies.

What is fasting?

First, we define What is fasting?, fasting is the result of not eating food for a few hours. There are several types of fasting depending on the amount of hours you spend without eating food, The one that is usually done is an 8 -hour fast, which would simply be worth not ingesting food during the night and skipping the first meal of the day, that is, breakfast. This is when glycogen levels are supposed to be lower, which activates the beneficial effects that are intended with fasting training. Glycogen in the liver, which are carbohydrate reserves, will be at a lower level after a long fasting period. Our body stores glycogen in two ways:

Muscular: It is used when the muscles are exercised.
In the liver: Decrease while we sleep, because the glycogen of the liver must supply the fuel brain.

Types of fasting that exist and its difficulty

There are different types of fasting, these will vary depending on the number of hours and the amounts of ingested kilocalories:

2/12: They spend 12 hours between intakes, it is usually at night. For example: if you have dinner at 10 pm and breakfast at 10 in the morning.
16/8: It is the best known, the eight -hour feed window is reduced alone and we fast for 16 hours.
20/4: You fast all day and give yourself a feast at night.
24 hours: It is a whole day without eating.
One Meal a Day: This fast consists of eating once a day. Without a fixed fast window.
5:2: Raised for a week, in which you eat normal 5 days and another two days you reduce your total caloric intake between 500-600 kcal.
Fasting on alternate days: It is fasting one day yes and another day.
EAT-STAP-EAT: It's about including one or two 24 -hour fasts in your week.
FMD: It consists of spending 5 days eating little (750 kcal).
WHEN: Try to skip a meal from time to time, without rules.

What happens in my metabolism if I train on an empty stomach?

This practice that has become fashionable, aims to force with fasting training to the body using fats as a source of energy. During the night, when we sleep there is a reduction in glycogen reserves. AND Taking advantage of that moment when glycogen levels are low, it will cause the body to access, so to speak, from the other source of energy during training. The energy source of which I speak is the fat that accumulates in the adipose tissue and of which there are enough reserves. This energy is obtained through a substance that secretes the pancreas called glucagon, and You will be in charge of converting fat into fuel. It is a slower and more expensive process for the body than to obtain the energy of glucose burning.

The usefulness of fasting according to the type of training

This is still a bit in the air and there are several studies, but let's continue: This topic, like the vast majority of nutrition issues, has as a response a "depends". And what does it depend on? It depends on the type of training. A moderate intensity has The effect that more fat is burned. This effect will be given more in resistance and low-intensity training or prolonged moderate efforts. This happens because carbohydrates, specifically, blood glucose, muscular and liver glycogen are mainly used at the beginning of training, and when the intensity reaches their first high peak. More or less fats begin to use after twenty or thirty minutes since we start training. There is an additional long -term effect, and it is that If the glycogen level is low, the cells will get used to burn more fat. Fasting training can improve performance in long races, because the intensity is lower and gains resistance on speed. In a race, a corridor spends a long time maintaining a short heart rate, so an improvement in the use of fat tank as a source of energy can improve performance. Concluding, fasting training It can be useful for resistance athletes where fats are used as the main energy source. However, if the training we are going to perform is high intensity, fasting loses its usefulness, as it produces the effect of reducing performance and activating glycogenesis, that is, of decomposing muscle proteins. In such a way that we would lose muscle mass and the body will not work correctly producing dizziness, fatigue or hypoglycemia.

Fasting training and fat loss

Normally, people perform this type of practices in order to lose weight and A fasting training does not involve losing weight, to lose weight the key is to spend more calories than they are ingested. And to get this, it doesn't matter if we do an emptyue sports or after having breakfast, in fact, if you have breakfast your training can be more intense, and perhaps burn more calories. The use of fats as fuel in fasting training can be useful for long -term resistance athletes as perhaps ultra background, but It is not demonstrated that it helps to lose weight or lose fat, this speaking in a context of people who are already trained. If what you are looking for is to lose body fat, read the following article: How to eliminate body fat through diet and sport.

What benefits do you have to train on low intensity sports?

Improvement of fat oxidation rate, increased enzymes that are involved in lipolysis, decrease in intramuscular triglycerides, increased hormones that stimulate fat mobilization, But no study shows that there are benefits in body fat loss. That is, for more fat mobilization during fasting training, The body cannot use all fatty acids as energy, so, fatty acids that were mobilized in your blood are stored again as fat, because the recommended intensity to do this strategy does not require much energy such as Hiit or Cross Training or intense career intervals. Fasting on an empty stomach It is not the most advisable if we are going to perform an intense sports activity, since the performance is going to be harmed. You will not feel with more strength, but If you exercise soft long if you can do it on an empty stomach. In the event that you are going to perform a high intensity physical activity, I recommend that you look at the following article: Pre-Entrene Food. What should I eat before going to box? Food is essential in any athlete to obtain good results.