Actual lipid consumption in sports training. Functional role and importance in metabolism

Abstract

Currently, many athletes, including coaches (except nutritionists), unilaterally evaluate the lipid
component, considering it mainly a source of energy. The large number of overweight (obese) people
has led to the fact that the main goal of rational nutrition has become the "fight" against excessive fat
consumption. However, fats (lipids) are indispensable food factors, as are, for example, proteins.
In highly developed countries, on average, no less than 40% of the daily energy requirement is
covered specifically by fat consumption.
Carbohydrates are also a source of energy. They can accumulate in the body in the form of glycogen.
However, the volume of glycogen stored in the body is immeasurably smaller than that of lipid
reserves. Moreover, if the intake of carbohydrates is excessive, the energy from their consumption is
also stored in the form of triacylglycerols, which are much more "convenient" for long-term storage
and metabolism, if necessary.
About 95% of the total volume of biologically accessible energy in the triacylglycerol molecule
contains residues of three long-chain fatty acids, and only 5% belongs to glycerol (glycerin) residues.
Oxidation of these fatty acids with a high energy value until their transformation into CO2 and water
is accompanied by the release of energy. The oxidation of fatty acids and carbohydrates has only one
final pathway: the citric acid cycle, the Krebs cycle, the tricarboxylic acid cycle.
The biological meaning of fat accumulation can be easily understood by comparison with fetal
metabolism. In the intrauterine environment, reserve lipids are lacking. The fetus receives the
nutrients it needs through the placenta from the mother's bloodstream. At the same time, this intake
of nutrients is continuous, unlike newborns and adults, who have different diets. The fetus does not
need energy reserves (reserve lipids) for long periods, as it is in a thermally regulated environment, it
is well protected, thanks to the amniotic fluid and the tissues of the mother's body, from mechanical
shocks. Only a short time before it is born, the body of the fetus creates its lipid stores. From the
moment of birth, these lipids perform three main functions in complex: a) they are energy reserves;
b) ensure thermal insulation, thanks to the subcutaneous fat layer; c) protect the child from external
mechanical actions and cushion internal mechanical movements of organs and systems.