eustress

The term eustress means "beneficial stress"—either psychological, physical (e.g., exercise), or biochemical/radiological (hormesis).

The word was introduced by endocrinologist Hans Selye (1907–1982) in 1976; he combined the Greek prefix eu- meaning "good", and the English word stress, to give the literal meaning "good stress". The Oxford English Dictionary traces early use of the word (in psychological usage) to 1968.