Using normative messages to influence behaviour has been receiving increased attention in the activity setting, with descriptive norms (DN; perception of what is commonly done) being associated with various forms of activity-related behaviour (Priebe & Spink, 2015). While the results have demonstrated a positive relationship for the most part, studies have yet to examine the effects of gender. This is surprising given that studies in other areas have found that the salience of norms on behaviour differs by gender (Elek et al., 2006). We explored the moderating effect of gender on the relationship between DN and muscular endurance in undergraduates. University students (N = 35) were randomly assigned to one of two conditions: control (nmale=10, nfemale=8) or DN (nmale=9, nfemale=8), and asked to perform two plank exercises to maximal exertion. Between planks, those in the DN condition were given a message that most others (similar to them) held their second plank 20% longer. Controlling for the initial plank time, ANCOVA results revealed a significant interaction effect, ηp2 = 0.12, indicating a strong effect. Means revealed that females in the descriptive norm condition held their second plank significantly longer than those in the control condition (adj. Cohen's d = 1.12), whereas there were no differences in plank hold times for males. If replicated, these results suggest that the effects of descriptive norms may differ between genders with females more likely than males to increase muscular endurance if they perceive more of their peers exhibiting a maximal effort on a similar task.