According to the first law of thermodynamics, energy is a constant, it cannot be generated from nothing, nor be destroyed, it can only be transformed. The energy of a system is transformed into heat, into the work of the system itself and into change of the energy in all the elements of the system, but this does not allow us to know what is the real distribution of energy between the various processes.
The second law of thermodynamics introduces the concept of "entropy", the measure of the "chaos" of the various processes. In each process there is an increase in entropy; this is measured as the "heat produced" by the process itself.
in fact, mobile is an "open system". Broadly speaking we could say that it oxidizes energy nutrients with the use of oxygen and expels carbon dioxide, water, urea and other waste products and, of course, also heat.
According to the first law of thermodynamics, with a positive energy balance, mass and energy are conserved; however, due to entropy, these are not fully maintained. Let's take an example to make it more understandable: the oxidation of a gram of glucose in a calorimetric bomb (instrument for measuring the energy content of a food) gives about 4 kilocalories (kcal), but the product of this transformation is totally heat. On the contrary, in a biological system, the oxidation of 1 mole of glucose gives about 38 Adenosine Tri-Phosphate (ATP), the rest is heat, water and carbon dioxide. This means that only 40% of the energy contained in a mole of glucose is stored by the body, the remaining 60% is expelled as a waste product.
The calorimetric bomb is a closed and inefficient system, our organism is an open and partially efficient system since it is capable of conserving part of the energy produced in a transformation. This is the reason why the first law of thermodynamics cannot be reported. to a living organism without taking entropy into account.
Furthermore, our organism is a system dependent on too many variables, subject to continuous external stimuli that lead it to implement relative changes. Of course it is true that we cannot create energy from nothing nor can we destroy it; instead we are able to take energy from substrates by oxidizing them to produce ATP. Therefore, the concept of caloric balance (calories IN - calories OUT), although correct, has some application limits.
We have said that the "oxidation of glucose has an" efficiency (ie energy retention) of about 40%; that of an amino acid has an efficiency of about 35%, but if this amino acid is contained in a protein the efficiency of its oxidation drops to about 27%. Therefore, the protein turnover, compared to oxidative glycolysis, has a capacity to retain energy less than about 8%. In theory, it could be possible to replace a certain amount of carbohydrates in the diet with a greater amount of protein, consuming more calories and obtaining the same caloric balance. If the increase of proteins in the diet could in some way increase the tissue protein turnover, it would have a double advantage; on the one hand, the guarantee of greater recovery after workouts, on the other, the increase in the dispersion of energy in the form of heat that would allow you to introduce more calories without running the risk of adipose deposition. D "on the other hand, it is not certain - indeed, it is not proven - that by increasing the protein in the diet beyond the normal limit - that, without studies in hand, it means everything and nothing - we can somehow favor tissue turnover. This aspect therefore remains somewhat hazy.
. Weight, however, is by no means the most important parameter. In fact, with each variation of the scale, we should ask ourselves: How much of the weight lost / gained is fat mass? How much muscle mass is instead?
Here it is useful to have a clear idea of the concept of "caloric destination", and above all of the effects that training constantly can have. Resistance training improves both global energy targeting and anabolic muscle building, optimizing glucose metabolism and promoting specific anabolism - thanks to hormonal (anabolic) and non-hormonal (such as AMPK) factors.
Everything would fall if, however, the diet did not include the various nutrients in the right quantities.
Read on: Importance of Protein in Training
