Use of a ketone body and a ketone body ester is disclosed for preserving glycogen and/or protein, thereby reducing muscle breakdown and improving endurance during exercise and promoting muscle recovery following exercise. The said compounds may also be used for retarding muscle wasting in aging and disease. Examples include esters of hydroxybutyrate monomers, in particular a monoester of D-ß-hydroxybutyrate with R-1,3-butanediol or with glycerol. Compositions containing ketone bodies or ketone body esters are also described.
