Introduction
Dietary supplementation in sport is a concept that, in many newbies, arouses wrong ideas and impressions.
For the avoidance of doubt, it is good to clarify, first of all, that there are no food supplements for sport capable of causing rapid weight loss or promoting dramatic increases in weight. perfomance athletics. There are few substances able to keep these promises, they belong to the category of drugs and, as such, have side effects that are particularly deleterious for the health of those who use them.
Only the use of an adequate training program, associated with a correct diet, possibly assisted by a responsible use of food supplements for sports, allows to obtain appreciable and stable results over time.
This article is dedicated to the description of the most used substances in the field of dietary supplementation for sport.
Caffeine
What it is and Effects
Caffeine stands out for the speed of absorption in the intestine and for the rapidity of metabolization; after its intake, therefore, the human body absorbs and metabolizes it extremely quickly.
This molecule is able to cross without difficulty the blood-brain barrier and, in pregnant women, the placenta; moreover, in pregnant women, it mixes with breast milk.
It is for the reasons just mentioned that, during pregnancy and breastfeeding, the woman must limit the intake of coffee and other foods that contain it.
Caffeine positively affects the performance athletics, as it stimulates the release of catecholamines, promoting the following effects:
- Increase in the frequency of breathing and therefore in blood oxygenation;
- Increased blood flow, cardiac output and blood supply to muscles;
- Stimulus on lipolysis, which favors the use of fats as energy fuel.
On the central nervous system, caffeine exerts analgesic effects, improves reflexes and the ability to concentrate, delaying the perception of fatigue.
Caffeine stimulates the metabolism and, thanks to its lipolytic properties, it is often used, as an additional ingredient, in the creation of slimming or anti-cellulite products.
Disadvantages of Caffeine
It should be noted that the regular intake of this substance causes addiction, with a consequent decrease in the desired effects. In addition, excessive doses of caffeine have negative effects on the whole organism and are associated with the appearance of symptoms such as hyperexcitation, headache, tremors, insomnia, nervousness and tachycardia. Although significant individual differences exist in this regard, in general the first important side effects appear at doses of 500-1000 mg / day.
How much caffeine in:
- a cup of coffee → 50-100 mg;
- a can of Coca Cola → 40 mg;
- a cup of tea → 50 mg;
- a hectogram of cocoa → 100 mg;
Since caffeine is a doping substance if present in the urine in concentrations above 12 mcg / ml (threshold achievable by consuming more than 350-400 mg of caffeine in the 60 minutes preceding the competition), its intake by athletes is NOT it's free.
Carnitine
What it is and Effects
Carnitine is an amino acid derivative whose synthesis, in the human body, takes place in the liver and kidney, starting from the amino acids methionine and lysine. A non-negligible amount of carnitine is also present in foods of animal origin such as meat and dairy products.
The metabolic role of carnitine is to promote the beta-oxidation of fatty acids for energy purposes, transporting them inside the mitochondria. By virtue of this function, carnitine is used as a fat-burning food supplement.
Use of sports carnitine
In particular, in the world of sport, the use of carnitine takes place with the aim of:
- Burn fat for energy and save glycogen;
- Limit the accumulation of lactate, as it promotes the conversion of lactic acid to acetyl-CoA.
Both effects would lead to an improvement in performance, as they would delay. the onset of fatigue; however, the efficacy of carnitine is questionable, as the various studies carried out to evaluate its energy potential have provided conflicting results.
Carnosine
What it is and Effects
Carnosine is a dipeptide, formed by alanine and histidine, naturally present in the muscles.
For some years now, carnosine has been used as a sports supplement, as it buffers lactate, reduces fatigue, improves performance and shortens recovery times.
Furthermore, researchers have recently proposed it as an anti-aging supplement, as it has an antioxidant and preventive action on the formation of AGEs (advanced glycosylation end products, excellent indicators of the risk of total and cardiovascular mortality).
Disadvantages of Carnosine
Carnosine intended as a food supplement for sports has particularly high production costs, which makes it a product that is not very popular among athletes.
Branched Amino Acids
What they are and their biological role during physical activity
The expression "branched chain amino acids" (or BCAAs) refers to a group of 3 essential amino acids, called leucine, isoleucine and valine.
During endurance exercise, branched chain amino acids play a prominent role: the human body, in fact, demolishes part of the muscle proteins rich in these amino acids for energy purposes.
Integration of Branched Amino Acids
In addition to supporting exercise by sparing structural proteins, the integration of branched chain amino acids can also serve to stimulate the growth of muscle mass.
Often, however, the users of these BCAA-based supplements, deceived by misleading messages, forget that, unless the sport activity is not particularly intense and prolonged, the use of these protein supplements is not necessary.
It should also be noted that the increase in muscle mass induced by the consumption of proteins or amino acids has a limit and that an excessive intake of these substances causes hepatic and renal overload.
Branched chain amino acids are useful in endurance sports, as they reduce the perception of the sense of fatigue. This happens because, using the same amino acid tryptophan carriers to pass the blood brain barrier, they prevent the tryptophan itself from reaching the brain, and transforming into serotonin, the neurotransmitter involved in the appearance of fatigue.
The integration with branched amino acids therefore reduces the synthesis of serotonin and with it the perception of fatigue during endurance exercise.
Creatine
What is it and its biological role
Creatine is an amino acid derivative naturally present in the human body, whose endogenous synthesis takes place in the liver and kidney, starting from the amino acids arginine, methionine and glycine.
Present mainly in the muscles, endogenous creatine is mainly responsible for supplying energy to the muscles in the form of ATP; here's how:
- In muscles, creatine is bound to a phosphate group via a breakable high-energy bond; the resulting molecule is called phosphocreatine (PCr).
- During intense short-term efforts (which involve the consumption of ATP), phosphocreatine transfers its phosphate group to ADP (product of physical exertion), generating new ATP according to a reversible reaction catalyzed by the creatine-kinase enzyme.
The reaction catalyzed by creatine kinase is as follows:
PCr + ADPIn skeletal muscles, creatine is provided with a phosphate group that the body uses, if necessary, for the re-synthesis of ATP.
The catabolism of creatine leads to the formation of creatinine, the excretion of which occurs through urine.
The human being recovers the amount of creatine lost through the process of endogenous synthesis and ready-to-eat food, in particular with the intake of meat. The endogenous synthesis process and dietary intake provide the body with about 1 gram of creatine per day.
It should be noted that an excessive dietary intake affects endogenous synthesis, reducing it, a bit like anabolic steroids do with testosterone.
Creatine as a Sports Supplement: Pros and Cons
Creatine intended as a sports supplement raises some perplexity, as its effectiveness does not find unanimous support in the scientific studies conducted in this regard.
In any case, according to pro-creatine studies (ie those that support the effectiveness of creatine as an effective sports supplement), this amino acid derivative would increase muscles, because:
- It would improve the hydration (therefore also the state of health) of the muscle cells, swelling. This consequence is an objective fact, confirmed by all the scientific studies conducted on creatine; however, it is a cause for concern because improved cellular hydration does not mean an increase in muscle mass;
- It would favor the expression of a gene, called MRF4, which is associated with the growth and strengthening of muscles;
- It would inhibit the expression of a gene, called myostatin, which is known to be a limiter of muscle growth in living beings;
- It would improve the contractile capacity of the muscles and reduce the sense of fatigue, ensuring more effective workouts.
Oral creatine supplementation has some undesirable effects, including:
- Weight gain
- Gastrointestinal disorders;
- Impaired kidney function after taking high doses for long periods of time.
Did you know that ...
Although there is a lot of confusion in this regard, creatine is not on the list of doping substances.
