Lipid composition and the ability of serum albumin to bind lipid components and products of their peroxidation were investigated in cyclists of different rating during moderate workloads. Ratios of subfractions of phospholipids and other lipid metabolites in blood serum albumin were determined by the method of thin-layer chromatography. Diene conjugates and diene ketones were found to be actively formed in plasma of highly trained cyclists in whom a high lipid capacity of albumin was associated with its low affinity for lipid hydroperoxides.