With its action, alcohol negatively affects sports performance. Obviously, its effects are dose dependent and if small quantities (30-40 grams per day for men and 20-30 g / day for women) are tolerable, high doses can seriously compromise sports performance.
L ‘ alcoletilico , despite the high energy value, not can be considered as a nutrient .
In the liver, the oxidation of 1 gram of alcohol still releases a high amount of energy (7 kcal, compared to 4 kcal of carbohydrates and proteins and 9 kcal of fats ).
However, it should be noted that the alcohol content shown on the label does not correspond to 1 g of alcohol but to 1 ml of ethanol which develops approximately 5.6 Kcal.
The high caloric content of alcohol is only one of the many negative effects of this substance which, with its action, alters most of the metabolic reactions that take place in our body. Let’s see in detail the most important.
Carbohydrate metabolism : inhibition of glycogenosynthesis and stimulation of glyconeolysis with consequent premature depletion of carbohydrate stocks.
Buffer systems: alcohol promotes the production and accumulation of acidic compounds such as lactate and ketone bodies, consequently lowering the pH of the blood . We remind you that metabolic acidosis (lowering of blood pH ) is responsible for symptoms such as fatigue, headache, nausea , vomiting and can lead to coma .
Blood: alcohol decreases the efficiency in the blood transport of iron , a mineral involved in the processes of ATP production and in the transport of oxygen. In particular, with its action it alters the synthesis of the different transferrin isoforms . This protein is involved in the transport of iron from the site of absorption to that of use or storage (in particular the liver).
Alcohol causes less absorption of vitamin B12 and folate. These two substances are fundamental because they regulate some important physiological processes. Their deficiency implies an increase in the volume of red blood cells, predisposing the subject to megaloblastic anemia and damage to the nervous system.
Alcohol is particularly toxic to mitochondria , the cellular organelles that produce energy.
Among other things, mitochondria synthesize heme, a chemical complex present in hemoglobin capable of binding oxygen. By associating the decline in heme production with reduced absorption of vitamin B12 and alteration of transferrin, oxygen transport to the tissues is seriously compromised.
This alteration negatively affects sports performance, especially in endurance activities such as running and cycling.
Alcohol also reduces testosterone levels by limiting protein synthesis up to 24 hours after its consumption, consequently the abuse of this substance compromises the increase in muscle mass .
Effects on the central nervous system : alterations in muscle contraction, worsening of reflexes, reaction time and coordination skills.
