Background. Health and well-being at work is generally assumed to be associated with sufficient physical and mental variation. Job rotation, where workers typically alternate between different physical tasks, is a popular initiative. Controlled experiments suggest that favourable effects are associated with alternations between mental and physical tasks, but little is known about this intervention in real work. The aims of this study were (1) to describe the occurrence of alternations between mental and physical tasks, and (2) to identify key determinants of such alternations.

Method. We developed a questionnaire combining established questions with specific questions about alternations. Workers from two occupations (industrial and non-industrial blue-collar work), in jobs containing both physical and mental tasks, were included in the study. 122 (55 females) out of 293 workers approached at four companies answered the questionnaire.

Results. On average, the workers alternated 3.5 times per day between mental and physical tasks. In the non-industrial companies, workers reported wanting more alternations than they had, while desired and actual alternations did not differ in the industrial companies. This effect of occupation on the difference between the number of alternations wanted and the actual alternations available was significant (p < 0.001). Furthermore, there was a general preference for performing a physical task after a mental task, and vice versa. This main effect of primarily performed task type (i.e. either physical or mental) on preferred subsequent task type was significant (p < 0.001). In a univariate analysis, gender appeared to be a strong determinant of the occurrence of alternations, but the effect was absorbed when adding the occupation variable.

Discussion. Within the studied companies, work offered alternations between mental and physical tasks and there was a preference among workers to alternate between tasks. Occupation rather than gender was a key determinant of the number of alternations reported.