Going for a run on an empty stomach in the morning, cycling to work, or simply going for a walk is a common trick for people who want to lose weight . The benefits of training on an empty stomach , beyond the early results for the physical, can be noted even on a mental level. Now, with the rise in popularity of intermittent fasting, doing physical exercise without first eating any type of food has become a ritual around the world. But, does it really work
, what do the experts say
Doing sports in a strategic fasting consists of training 4 hours after the last food intakesolids or beverages with caloric power.One of the main objectives of fasting sports is to increase performance to lose weight and lose fat more effectively.
And it is that the key to fasting sports, as explained from the runtastic website, is that glycogen reserves are quite limited, so, after a night of fasting, glycogen reserves (especially those of the liver) have reduced considerably. When there is not enough energy available from carbohydrates, the body begins to burn fat.
The same note is made from the Gym-in website, where they explain that the body, when exercising, converts theglycogen stores into glucose to provide energy.Not having enough glycogen, the body begins to use fat as an energy source.As a consequence of that, insulin will drop after exercising.
It should be noted that this occurs when the level of training is low or moderate (such as aerobic exercises) and when performing certain sports and activities. In addition, this type of practice is recommended for those who train periodically and are used to playing sports. If you are in the middle of the sports initiation phase or you go to the gym only from time to time, you will only notice the benefits incertain specific exercises and you will have to get your muscles used to the new dynamics.
For example, research in this regard indicates that if we are going to perform high-intensity training , there is no difference between training fasted or having food and the oxidation of lipids that occurs is similar.However, there are things and types of training in which it may be advisable to train fasted to improve glucose tolerance and insulin sensitivity.
PROS AND CONS
Although there is no doubt that practicing sports on an empty stomach will offer a series of benefits, it must be borne in mind that certain guidelines and aspects must be followed in order not to turn this practice into something harmful or counterproductive. Here we list some of the pros and cons supported by studies and experts:
1. You burn more fat
As we have already mentioned, a study reported that fats are better metabolized if we exercise without eating any food. When our body gets used to using fats as a source of energy instead of carbohydrates, this process gradually becomes more and more efficient.
This means that as training hours accumulate, fats will be more easily mobilized from their deposits and metabolized as energy.
2. Promotes performance
In certain cases, exercising on an empty stomach improves performance.This maximum only applies to endurance activities such as marathons or long races. The body is much lighter, so it can withstand low-intensity sports much more.
3. Improves sensitivity to insulin
Insulin is the hormone responsible for capturing glucose from the blood and transporting it to the receptors responsible for using that glucose or storing it.
The fact of training fasted will mean that from the first moment we start the exercise, the level of insulin in the blood is minimal or non-existent, so other mechanisms must begin to be used to make this contribution.
When we carry out a physical activity of a moderate or high nature, the supply of glucose to the muscle after 20 minutes or half an hour , is carried out without the need for insulin.
4. Improves muscular aerobic performance
One of the main advantages of following this fasting-sport practice is that it improves muscular aerobic performance. In this way, a better oxygenation of the tissues is favored.
It also improves themetabolic flexibility, cholesterol and triglycerides in the blood
5. More energetic and happy
And it is proven that going for a run, going to the gym, swimming… on an empty stomach, makes one happier and face the day in a better mood. By breaking down fat to produce energy, ketone bodies are produced that are used by the brain as a source of energy. In addition, by improving oxygenation in general , the brain has more energy available, which inevitably translates into an improved mood. .
1. Decrease in muscle mass
Despite the fact that experts assure that muscles can be tonedThrough fasting sports, it is important to take into account proteins , another of the elements that the body uses as a source of energy and that are important when it comes to achieving muscle mass.
Therefore, when the body uses these proteins to produce energy ,muscle mass can be seen to decrease.
2. It is not appropriate for strength exercises
Fasting training at high intensities is not going to be the most indicated if you want to eliminate excess fat . The body can NOT use all these fatty acids as energy , therefore, all these fatty acids that were mobilized in your blood, are again stored as fat, because theThe recommended intensity to do this strategy does not require much energy.
Consequently, our body will need to obtain energy from anywhere, which includes the muscles. In addition, performing 100% will surely not be possible when the duration of the training is prolonged ( beyond 2 hours ) if its intensity is high .
For this reason, and even if you have started training on an empty stomach, it is convenient to start eating food after 90 minutes.
3.Fatigue and fainting
When exercising on an empty stomach, other effects must be taken into account apart from fat loss that may make it not recommended for all people to carry out this practice and, above all, it is not advisable to do it excessively.
To begin with, glycogen is the main source of energy used by our body, so exercising on an empty stomach can alter its functioning, causing fainting or dizziness, especially if you are not used to it.