Importance of Proteins in Training

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Any sportsman craves the chance to lose fat and maintain or increase their lean mass.

But is it really possible, with nutrition alone, to change body composition without necessarily going through bulking and cutting? Perhaps, but it is not certain that theentity of the results can be defined satisfactory for everyone. Let's see how.

Nutrients and Hormones

Diet, hormones and the impact of insulin

First of all, it is crucial not to lose sight of the metabolic impact of energy nutrients (proteins, carbohydrates and fats) on the only diet-dependent anabolic and anti-catabolic hormone (which promotes the construction of tissues and / or preserves their integrity): insulin.

Having said that, it is necessary to clarify some fundamental concepts concerning this chemical mediator:

  • Insulin has anti-catabolic effects on both muscle and adipose tissue; in reference to the latter, high levels of insulin have the ability to inhibit lipolysis (breakdown of fatty acids for energy purposes), hindering weight loss
  • The anabolic effects of insulin on muscle tissue are less evident than the anti-catabolic ones. These two functions may seem identical but they are not; anabolism means "to build", anti-catabolism means "to hinder destruction"
  • Insulin alone, in lack of essential amino acids (especially leucine) does not fully exert its protective effect on muscle tissue
  • Insulin sensitivity to muscle tissue can be variable; when it is low, the subject has a tendency to hyperglycemia and to gain weight. Get better with physical activity
  • High insulinemia (insulin in the blood) hinders the increase in somatotropin.

Note: the third anabolic hormone, also DON'T diet-dependent and stimulated by sports activity, is testosterone.

Since the increase in GH during intense and prolonged physical exercise is stimulated by a precariousness of the glycemia, giving somatotropin an essentially catabolic function, and considering the fact that as glycemia and insulin increase, its levels return to basal conditions , with the aim of supporting tissue anabolism or counteracting its catabolism, it is reasonable to focus above all on insulin levels - instead also influenced by the meal.

  • Insulin DON'T it is stimulated only by carbohydrates, but also by amino acids and energy lipids or part of them
  • Each calorie nutrient has a different insulin-stimulating capacity, a characteristic that also depends a lot on the quantities.

However, considering the fact that cereals and derivatives make up a large part of the country's diet, we could say that it is mainly carbohydrates that increase the blood levels of this hormone.

To facilitate the understanding of these concepts we make a small similarity: we assume that insulin is a "chief carpenter", the synthetic enzymes the "masons" and the carbohydrates, proteins, fats of the "bricks" (different from each other). Chief carpenter talks to muscle masons of preserve more possible contractile and other fibers to rebuild glycogen stores (in the absence of dietary carbohydrates, it can stimulate neoglucogenesis in the liver using some amino acids); however, it also communicates to the masons of the adipose tissue to increase the fat content of the adipocytes (the fatty acids are "bricks" that the body is capable of obtaining also from the other two, when they are in excess). So, by the action of insulin:

  • The fats end up in the adipose tissue. The reader should not be misled; in fact, the anabolic and catabolic process on the adipocytes is continuous; in order not to gain weight, it is sufficient that the right balance is maintained
  • Amino acids serve to preserve muscle tissue; if in excess, they can be converted into both glucose and fatty acids. Hence, some amino acids can perform the function of dietary carbohydrates, although not with the same efficiency, but not the other way around.
  • Glucose serves to preserve blood sugar and glycogen stores; if in excess, it can be converted into fatty acids.

All this basically means three things:

  1. Insulin is very useful for muscle recovery but, if associated with an excess of calories, it promotes adipose storage
  2. Excessive quantities of food, therefore of calories, always make you fat, regardless of the composition of the meal
  3. Insulin levels can be managed with diet, while GH and testosterone secretion cannot. On the contrary, training has a very positive effect on them.

This means that "guessing" the right caloric balance and the correct distribution of nutrients is crucial to obtaining a good bodyrecomposition.

Proteins and Protein Synthesis

Proteine e "lean body mass sparing effect"

At the same time, it seems that protein synthesis does not depend strictly, or exclusively, on insulin action, and that it can also occur in different ways - obviously, this reasoning does not take into account theentity of this process. Some studies show that by integrating BCAAs in the post workout it is possible to stimulate protein synthesis, without however buffering the proteolysis. An incomplete effect.

As mentioned above, insulin is not only stimulated by glucose, but also by amino acids. If taken individually, some of these can also be highly insulin-stimulating, while others are not. This means that the insulin-stimulating capacity of dietary proteins depends on their composition. For example, the peptides of dairy products have a high glycemic index, while, for example, those of meat less. Taking the latter after training could therefore enjoy a triple effect:

  1. Protein synthesis thanks to the availability of BCAAs
  2. Anti catabolico
  3. Maintenance of lipolytic activity by moderation of insulin.

Based on this reasoning, it could be deduced that the winning strategy is to increase the protein in the diet while maintaining a sufficient glucose fraction only to support training. It would not be flawed, except for the fact that there are numerous glucose-dependent tissues in the body. Hence, the carbohydrate fraction cannot be as reduced as one would like. Furthermore, the organism is forced to produce them starting from amino acids, which obviously will have to increase in quantity by inexorably increasing the insulinemia, however making "more effort" to obtain a few carbohydrates that could easily be introduced with food. Let us not forget that glucose is necessary for the maintenance of certain endocrine functions, among which nothing less than the thyroid; the T3 produced by the thyroid is the hormonal mediator that regulates the speed of cellular metabolism of each body tissue. It would therefore be stupid to reduce carbohydrates too much, having negative repercussions on the basal metabolic rate.

Furthermore, the scientific community has always been skeptical about the excessive increase of proteins in the diet. The fear is that these can strain the kidneys and liver, predisposing to even serious discomfort. In reality, it is not "quite" like that. Despite the recommendations of the research bodies - which obviously must respect safety margins - cases of nephrological and hepatic diseases attributable to excess protein in healthy people are almost non-existent.

No studies report significant changes in disease parameters with protein doses reaching 3,2 gx kg of normal weight; on the other hand, there is no doubt that nitrogen waste can increase and, in the long term, it is not possible to establish how these can affect the state of health.

Other studies that examine power athletes have shown that, to obtain a positive nitrogen balance (therefore to increase nitrogen waste), the sample needed at least 2,2 g of protein per kg of weight. This requirement increased to 3,2 / 4 g per kg of weight in athletes engaged in both power training and aerobic training.

However, the individual studies are easily contestable; these numbers should therefore simply be taken as a trace or an idea to perfect the diet aimed at bodyrecomposition.

Read on: Glucide Requirements in Training
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