Introduction: Precarious manhood theory posits that manhood is socially constructed and must be earned by acquiring masculine capital. Previous research has suggested that there may be a link between threatened masculinity and a higher drive for muscularity. The current study tested this hypothesis experimentally. Methods: Male undergraduate students (N = 395) were either told that they did poorly on a cognitive task explicitly tied to a masculinity norm (i.e., future earning potential) or they were not given any feedback. Results: Participants in the masculinity threat condition subsequently reported a higher drive for muscularity than did those in the control condition. Sexual orientation did not moderate this effect. Discussion: One of the ways in which men feel that they must earn masculine capital is by having a muscular body. Drive for muscularity is heightened in situations that prime threatened masculinity. The current findings imply practice implications for men struggling with negative body image.