A kilogram that is normally lost with a diet that is not excessively low-calorie and nutrient-balanced, combined with an adequate physical activity program, has a value of about 7000 kcal and consists largely (75-80%) of fat mass and rest (20-25 %) from fat-free mass.
On the other hand, if you have diets that are too restrictive (too few calories) or unbalanced (too few carbohydrates, too little or too much protein, etc.) and you do not carry out an adequate physical activity program, you will lose more and more lean mass.
Not only that, for every kilo of fat-free mass lost, the metabolism will decrease by about 40 kcal.
Therefore, after a certain period of starvation and a few kilos dropped, when subjects return to “normal food”, they find a slower metabolism, they are no longer stressed, as if their body had more lean mass.
In these conditions, they regain the lost pounds even with interests, because drastic, unbalanced or monotonous diets are the first cause of yo-yo syndrome (weight fluctuations characterized by rapid loss and rapid recovery, often to a higher level). We also remind you that physical activity not only helps to preserve lean mass, but specific exercises, as described below, tone, strengthen and give your muscles more strength.
How to approach physical activity
If you lead a sedentary lifestyle, before starting any physical activity, it is important to undergo a medical examination to assess your physical condition and especially the health of your musculoskeletal system and cardiovascular system: an electrocardiogram under the level of exertion to tell what is the maximum intensity that your body can withstand.
It is also important to pay attention to the quantity and quality of physical activity. A good training program must be done by professionals such as a physical activity doctor or a certified personal fitness trainer.
There is no one-size-fits-all solution: therefore, try to talk to an expert to choose an exercise activity that you like, that you can practice consistently and that is compatible with your plans and lifestyle.
In any case, remember that if you are obese, overweight or have not been physically active for a long time, you will need to start carefully and gradually reach the goal you have set for yourself.
If you have played sports, remember that some “land” sports, such as running or soccer and other typically competitive sports, may not be ideal, at least initially, because they can put excessive stress on weight-bearing muscles and joints. in excess. Prefer activities such as walking, cycling, swimming or water aerobics: these activities have the advantage of allowing a significant energy expenditure without excessive stress on the joints.
Physical activity to burn fat
The most suitable physical activity for fat burning is aerobic (such as walking, cycling, etc.) performed at a medium intensity. At this level of intensity, there is also a slight increase in muscle tone and cardiovascular adaptation begins.
To understand what the right intensity is without measuring or doing hard-to-follow calculations, you can do a self-talk test that helps you understand whether or not you’re maintaining the right intensity by “observing” your breath.
As mentioned before, remember that to “burn” fat, your metabolism must be working; therefore, in order to better preserve muscle mass, you will also need to devote some time to muscle strengthening exercises (see the next chapter).
How and how much physical activity to do
In addition to intensity, regularity of training is important. According to the SIO (Italian Society of Obesitology) and ADI (Italian Dietetic Association) guidelines for adults, at least 150 minutes of moderate-intensity aerobic physical activity per week is recommended to prevent weight gain, in addition to a balanced diet. exercised for at least 10 consecutive minutes.
In overweight and obese individuals who followed a balanced low-calorie diet, the weight loss benefits were observed to increase with increasing time devoted to physical activity:
- less than 150 minutes per week leads to minimal weight reduction;
- 150-250 minutes per week leads to a slight reduction (2-3 kg in 6-12 months);
- 250-400 minutes per week offers a reduction of approximately 5.0-7.5 kg in 6-12 months.
To improve the speed and quality of weight loss, aerobic work can be combined with anaerobic muscle strengthening. With an increase in muscle mass, there is an important increase in basal metabolism, that is, the consumption of calories consumed at rest increases.