'workout' originates from the English words 'work' and 'out', where 'work' meant 'activity involving mental or physical effort' and 'out' indicated 'outside or beyond'.

'work out' was initially used in the 19th century to mean 'to solve or calculate', and eventually evolved into the modern English noun 'workout' referring to physical exercise.

Initially, it meant 'to solve or calculate', but over time it evolved into its current meaning of 'a session of physical exercise'.