14 Jul Exercise
Since the middle of the 20th century and today there is a consensus in the world population that health and in this case, “good” health, is the result of countless hours in the gym. This idea has become such a real health dogma that even the school system has been forced to establish, in its course of studies, more time for physical exercise.
Medicine emphasizes that we have been a nomadic and collecting society from our earliest dawn as human beings; It even goes so far as to say that two centuries ago we had better health because we were a sedentary society since we worked the land.
However, before entering the complicated world of biochemistry and why it is not biologically possible to obtain greater health by physically destroying ourselves in a gymnasium, let’s do a simple analysis. What jungle animal does physical exercise for simple pleasure ?. A tiger has never been seen training in the jungle to be fit for the next day’s hunting. In reality, every animal, including the human being, moves only for reasons of survival, that is to say: to look for food and with great intelligence, for mating and to escape its predators or dangers. Outside of these survival reasons, the animal is at rest almost all the time.
If we analyze this in a little more depth, we must focus on the only organelle the mitochondria (eg component of a cell), which allows transforming potential energy sources into kinetic energy (ie movement) especially in muscle tissue, a change that must occur in seconds during a physical effort.
In general, the energy required to carry out all the activities of our body is derived from the breakdown of the single-molecule phosphate bonds, ATP or adenosine tri-phosphate, graphed as follows.
- Adenosina PO3 PO3 PO3 (Adenosin Tri-Fosfato)
In activity the body can transform ATP into ADP or adenosine di-phosphate and even AMP or adenosine monophosphate.
- Adenosina PO3 PO3 (Adenosin Di-fosfato)
- Adenosina PO3 (Adenosin Mono-Fosfato)
With each breakdown of the phosphate radical, 7300 calories of energy are obtained to provoke the contractile activity of the muscle tissue, giving maximum muscle strength for a period of only 3 seconds, in the athlete entering well. In other words, this energy is enough to run 50 meters.
However, within the mitochondria that are a special part of muscle tissue, their predilection for obtaining rapid energy is the Phosgene Energy System; They extract energy by breaking a molecule called phosphocreatine and breaking it down into creatine and phosphate. This mechanism makes available 10,300 cal / mol which can be translated as a high number, but in reality this value implies a muscular contractile force for a maximum of 8-10 seconds, enough to run 100 meters in a trained person.
As if this were not enough, once the phosgene system is depleted, the muscle can extract even more energy from its own reserves of glucose in the form of glycogen; This process is known as glycolysis and in muscle tissue it occurs without the need for oxygen or in anaerobic conditions.
Normally during glycolysis one glucose molecule breaks down to form two pyruvic acid molecules that will give rise to four (4) ATP molecules. When there is no oxygen, such as at the time of exercise where energy is immediately required, pyruvic acid is converted into lactic acid (which by the way is toxic and very painful) which diffuses into the surrounding tissue of the muscle cell. Lactic acid forms 2.5 times more ATP and in half the time than the phosgene system giving rise to 1.3 to 1.6 minutes of maximum muscular activity but with less force, that is, enough force to run 500 meters.
To recap, the energy for exercise in a trained athlete is obtained as follows:
- Basic break of the ATP 3 seconds (50 mts of race)
- Phosgene System 8-10 seconds (100 mts of race)
- Glycogen / Lactic Acid 1.3 – 1.6 minutes (500 mts of running)
With this basic understanding of energy transformation, it would be foolish to ask a person to make physical efforts of 30 minutes or worse, of an hour or more. The muscle only has enough energy to safeguard life, that is, enough to run away and escape the attack of a predator. So how is it possible that there are athletes who run for hours, even days without dying in the attempt? To explain this interesting modern activity, which has no place in the animal instinct (eg only the human being moves without having to), the books of physiology are based on indicating that during a sustained physical effort (ie they do not refer to what amount of time ) The body uses potential energy reserves in the form of fat collected in fatty or fatty tissue.
Until now this explanation can be obtained from any physiology book, and yet so far no medical student loses his sanity when he should. Imagine that we only have energy for 1.6 minutes maximum and this only in the trained athlete. Knowing this, it would be impossible and inhumane to ask a patient to make physical efforts of 30 minutes or even an hour. So why does the doctor continue to indicate sport to his patients? The answer is simple, because physiology books say that once these energy systems are depleted, the body will automatically begin to use the potential energy stored within of fatty tissue or fatty tissue. All this says the physiology texts, using fatty acids.