The lipid composition of membranes of erythrocytes in athletes of cyclic types of sport with qualification from first adult class to Master of Sports and persons doing no sports was analyzed. The qualitative and quantitative analysis of phospholipid fractions and fatty-acid specter of sphingomyelin and phosphatidylcholine was implemented. In athletes, amount of sphingomyelin and phosphatidylcholine and percentage content of phosphatidylcholine were significantly increased. The percentage content of kefalin was also decreased. The ratio of sphingomyelin/phosphatidylcholine was lower on 52.3%. In fatty-acid specter of sphingomyelin and phosphatidylcholine of athletes the percentage of C14:0 and C16:0 was decreased. In phosphatidylcholine increase of content of C16:1 was noted and in sphingomyelin content of C18:3 was increased. The ratio of sums of saturated fatty acids/polyunsaturated fatty acids were lower in athletes. The study results testify significant alterations in membranes of erythrocytes caused by regular physical loads and probably favoring increase of functional activity.