PT Personal Trainers

Train in Fast!? Depends!

Fasting training has been a dynamic applied by many people, but it has generated controversy.
There is agreement and disagreement, but in the end it is important to know the advantages and disadvantages of fasting.


Fasting training is related to fat loss, since glycogen stores are low which will cause the body to recruit fat to create energy.
However, we know that the practice of fasting also leads to the use of glycogen in muscle mass, which may not be beneficial, since its use leads to loss of muscle mass.
When talking about fat loss you need to realize the type of workout that the person performs.


Low blood glucose is one of the conditions for the production of growth hormone (HC) and, simultaneously, the aerobiosis stimulates the production of this hormone anabolic.
At the same time, the HC has an action, of degradation of fats, being responsible for the conversion of fats into energy.
When speaking of fasting training, it is considered a short / medium duration and low intensity workout, in order to ensure that fats are used.
Higher intensities are to be avoided since they will lead to the release of hepatic glycogen and cortisol, which will interfere with the release of HC.
Fasting training may lead to a loss of body fat, but will it be the best way to do it?


The pace of some people is conducive to sports practice in the morning.
There is an acceleration of the body early, improving daily well-being.
The body and mind are more relaxed.


Fasting physical exercise burns muscle mass. Use of glycogen to obtain glucose as an energy source.

It may be a risk, the metabolic processes of fat and the amount of glucose in the blood are variable, can lead to hypoglycaemia.
The brain consumes and needs sugar. In the absence of this sugar, this will produce ketone bodies, raising the acidity in the blood.
The risk of fatigue of micro muscular injuries is increased.


When performing fasting aerobic exercise, the duration of the training should not exceed 45 minutes, so as not to wear away the reserves necessary for the proper functioning of the organism.

So, the more trained you are, the less risk you have with this type of training, and you can achieve some fat loss with this workout. However, if you are not a trained person, it is best to start with other types of training.

Come and optimize your training to the maximum, so contact us!

Text by Carlos Pinto