Effects of the emerging nonexerciser stereotype on performance on a fatiguing task in active and less active healthy young adults Perceptions of active and inactive people are conveyed by society and a nonexerciser stereotype has emerged. Past research has focused of information formation with nonexercisers perceived, by both exercising and non-exercising people, as less healthy, less energetic, unfit, less strong and weaker. We know, however, that stereotype threat can contribute to the underperformance of individuals belonging to a range of negatively stereotyped groups and in a number of domains. Furthermore, fatigue is an important indicator of performance. The present study sought to observe the effect of the nonexerciser stereotype on performance in a fatiguing task. We used physical activity questionnaires to recruit and compare 13 male nonexercisers and 13 male exercisers’ performance on the fatiguing task, consisting of executing intermittent contractions until exhaustion. Participants completed a familiarisation session as well as stereotypical and nullified sessions. A significant condition main effect (i.e., nullified and stereotypical) was shown, F(1, 24) = 40.42, p < .001, η2 = .63. Indeed, this condition main effect was contrary to classic stereotype threat effects, as nonexercisers under stereotype threat improved their performance as revealed by increased time to exhaustion on the fatiguing task. Exercisers also increased their performance when under stereotype threat, in line with the stereotype lift effect. A significant condition main effect also appeared for the rate of perceived exertion (RPE) slope, F(1, 24) = 6.88, p = .015, η2 = .23. The RPE increase was greated in the nullified condition as compared to the stereotypical condition. These valuable results observed for rate RPE allow to suggest that RPE could be a mechanism through which performance on a fatiguing task may be affected. Furthermore, this study is encouraging, in that it revealed that nonexercisers’ performance on a prolonged fatiguing task was not decreased by the negative nonexerciser stereotype.