From the healthiergang writer, majoring in Medicine and Surgery.
Run Fasting
Summer is coming and with it we all feel the need to get in shape. So, let's get rid of fitness magazines and unlikely articles on the effectiveness of the grapefruit diet ...
Those who are "smarter" rely on fat burners or try in some way to increase their consumption to achieve the much-hoped-for silhouette. In this field, too, different theories rage on several fronts.
Running is undoubtedly the most used activity for slimming purposes: free and practicable for more or less five, obviously at their own pace and times. Have you ever heard that it is necessary to run for more than 20 consecutive minutes to consume fat? Or that it is necessary to remain in the "lipolytic band"? The same goes for "running fast".
For years we have been looking for the best method to burn as much fat tissue as possible, but is this method really effective?
First of all, let's clarify the concept that running on an empty stomach really burns more fat! So far, nothing to object ... but what impact does it have on weight loss? Is it really such an essential strategy?
Does running on an empty stomach really make you lose weight?
During normal daily activities, the body burns a mix of carbohydrates and fats to produce the energy it needs. This occurs in varying proportions: the greater the intensity of the activity carried out, the greater the percentage of carbohydrates consumed. This is the physiological foundation behind the "running in the lipolytic belt".
An adult of about 70 kg who runs in the lipolytic belt will always consume 70% carbohydrates and only 30% fat. What does all this mean?
Take for example a 70 kg man who runs around 70% of his HRM for an hour (therefore in full lipolytic range). Approximately the calorie expenditure is 580 kcal, but only 30% of these are obtained from lipids ... therefore 174 kcal.
1 g of fat is equivalent to 7 kcal (not 9 kcal because we eliminate the aqueous component of the adipose tissue in the calculation), so in the end we consumed just under 25 g of fat ... a rather poor result, what do you think?
It is clear that it is not possible to base one's weight loss only on running in the lipolytic range, what matters is the daily caloric balance ... and the same obviously applies to running on an empty stomach.
In the latter case, having our body need to preserve blood sugar above 70 mg / dl, in relation to the amount of glycogen present in the liver (lower as soon as you wake up, after fasting at night), it will mobilize a greater share of fat for energy purposes.
"Unfortunately" or fortunately, the body is capable of self-regulating and maintaining the right homeostasis throughout the day, so this metabolic adaptation will only be present in "acute" and will not persist in the hours following training ... so if you have consumed more fat during training, you will consume less at rest, and vice versa, if you have consumed more glycogen, you will consume less later on against the fat.
On balance, therefore, whether you consume more carbohydrates or fats during training does not matter, what matters is the total balance at the end of the day, or better still at the weekend.
Indeed, I will tell you more, it is much better to consume sugars, as these regulate lipid metabolism and not vice versa. In fact, a famous phrase in the academic world says "fat burns on the flame of carbohydrates".
Work out on an empty stomach if you prefer, some choose this solution because they leave the rest of the day free for other commitments ... but what matters is the quantity and quality of the work done.
If you decide to use running for slimming purposes, the only valid strategy is to travel as many km as possible, since the caloric balance at the end of the day makes the difference.
To conclude, I leave you another little tip.
The Respiratory Quotient
Avoid covering yourself as if you were on the summit of Everest ... sweating more will not help you lose weight, on the contrary it will reduce the amount of fat burned.
Because the more the body temperature rises, the more the subcutaneous blood flow increases in order to disperse heat. Which conflicts with the demand for more muscle tissue intake ... the heart rate then increases in an attempt to meet both demands.
Moral of the story? With the same work (distance traveled x body weight) the respiratory quotient shifts towards the consumption of carbohydrates.
The respiratory quotient, also known as RER (Respiratory Exchange Rate), is nothing more than the ratio between the carbon dioxide produced by cellular metabolism and eliminated with respiration, and the oxygen consumed in the unit of time.
This value changes depending on the energy substrate that is used, therefore depending on whether the body uses carbohydrates, lipids or proteins for energy purposes. In fact the carbon dioxide produced with respect to the oxygen consumed is different for the 3 substrates.
All this is due to the different structure of these substances which determines a different release of carbon through carbon dioxide. Therefore, through the measurement of the respiratory quotient, it is possible to know the percentage of fats and sugars that is consumed in that instant.
The value of the respiratory quotient can vary between 0,7 and 1: 0,7 is the value obtained when only fat is consumed; 1 is the value obtained when only sugars are consumed.
If we measure the QR in a person who runs while wearing heavy clothing to increase sweating, we will notice that this is very close to 1.
Running in these conditions is not only useless, it is also dangerous, precisely because excessive clothing will not allow adequate evaporation of sweat so there is a risk that the body temperature rises so much as to cause fainting or fainting.
If you want to lose weight, the only solution is to exercise and follow a correct diet, leave all these "tricks" closed in the drawer and concentrate on a few but essential concepts.
Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you are concerned, consult a health professional before taking dietary supplements or making major changes to your diet.
