Red blood cells state and calcium content of in the blood plasma during physical activity in marathon runners of various qualifications

The aim of the work is to investigate the morpho-functional state of peripheral blood erythrocytes and the content of Ca2+ in the blood plasma during physical exercise in marathoners of different qualifications.Material and methods. The studies were conducted in three groups of marathoners aged 20–25 years old with conditionally high, medium and low performance. Exercise was performed for 90 minutes on a bicycle ergometer with a given power. The study of peripheral blood erythrocytes was performed before and after exercise. The osmotic resistance of erythrocytes, the content of Ca2+ and free fatty acids in the blood were determined. Morphological study of erythrocytes was performed using a scanning electron microscope and stained by standard techniques. The red blood cell form index was determined by a special formula. Changing the content of Ca2+ enhances lipid melting, increases membrane fluidity and increases surface tension, with the result that the discocytes are stretched and thinned, the central pits deepen and the surface roughness increases, the volume and number of conical pores, and peripheral blood erythrocytes density.Results. Marathon runners of different groups after physical exercise differed in terms of the frequency of cardiac sweeps, the content of free fatty acids and the osmotic resistance of red blood cells. This is closely correlated with changes in the electrolyte and metric composition of erythrocytes and the presence of their reversible and irreversible forms in the general circulation after exercise. Conclutions. Physical activity causes structural and functional reorganization of erythrocytes, which is based on a change in their microelement composition, a decrease in osmotic resistance, mainly in poorly trained marathoners, and the appearance of various forms of erythrocytes against the background of the destruction of degenerative forms and an increase in the active release of young forms, which is a sign of high adaptive capacity in highly skilled athletes.