Long Workdays versus Restdays: Assessing Fatigue and Alertness with a Portable Performance Battery

A test battery designed to assess psychological/behavioral fatigue was used to compare restdays to a workweek of five 12-hr days at a data entry job simulation. Across both workdays and restdays, the battery was presented at regular intervals to test for fatigue effects and diurnal variations. Increased data entry errors across the workday and the workweek as well as subjective reports of increased tiredness on workdays indicated that the work regimen was fatiguing. Test battery performance paralleled those results. On workdays, as compared with restdays, grammatical reasoning was faster but less accurate; digit addition was slower; simple, dual, and choice reaction times were slower; and hand steadiness decreased. The results demonstrated the sensitivity of the battery to long hours of work. The results are discussed in terms of work-rest differences, changes across the workweek, diurnal variations, and cognitive demand.