Abstract: The present invention provides a compound for use in preventing or treating overtraining in a subject, wherein the compound is selected from (i) (R)-3-hydroxybutyrate; (ii) an ester of (R)-3-hydroxybutyrate; and (iii) an oligomer obtainable by oligomerising (R)-3-hydroxybutyrate moieties; or a pharmaceutically acceptable salt or solvate thereof.

Abstract: The present invention provides a compound for use in treating cancer cachexia in a subject, wherein the compound is of general formula I: (I) or a pharmaceutically acceptable salt or solvate thereof; wherein —R1 is a C1-C6 alkyl group, which alkyl group carries up to five —OR2 substituents, wherein R2 represents hydrogen, or C1-C6 alkyl or wherein —OR2 represents a (R)-3-hydroxybutyrate moiety; or —R1 is a moiety derived from an alcohol HOR1, wherein said alcohol is a sugar. Typically, the invention also provides treatment of the conditions associated with cachexia, such as muscle wasting.