peer reviewed ; Maintaining productivity is of primary importance in organizational settings. Nowadays, the pressure for work efficacy is required until advanced age given the increased longevity in western societies. Worryingly, performing a work for a long-lasting duration may induce cognitive fatigue, which can alter job performance or cause work accidents. Regarding laboratory studies, cognitive fatigue, as induced in Time-on-Task designs, has been shown to increase reaction times (RTs). According to the Effort-Recovery Model (ERM), work breaks are able to relieve cognitive fatigue and to maintain performance. However, few studies have investigated age-related effects in such a context. In this study, young, middle-aged, and older people performed a 160-min Stroop task in a “NoBreak” or a “Breaks” condition. To assess changes in RTs with Time-on-Task, the task duration was divided into four 40-min blocks in which the ex-Gaussian τ parameter (i.e., an index of longer RTs) was extracted from individual RT data. Our main results showed that young and middle-aged people increased their τ with Time-on-Task while older people did not. Importantly, participants in the NoBreak condition increased their τ with Time-on-Task while those in the Breaks condition kept this parameter constant, suggesting a beneficial effect of breaks independently of age.