Effects of a Motivational Video on Self-efficacy and Muscular Endurance Kayode Damali Department of Interdisciplinary Studies, Manchester Metropolitan University Abstract Increasing an individual’s self-efficacy can enhance muscular endurance performance. Pre-game speeches are one way of achieving this, but using them on a video prior to exercise has not been examined. A convenience sample of 45 male participants, with a mean age of 20.9 years (SD = 1.7), watched either a motivational or non-motivational video before completing a self-efficacy scale and doing the plank exercise. An independent t-test revealed that participants who watched the motivational video significantly improved their muscular endurance performance compared with participants who watched the non-motivational video (t = 1.771, df = 43, p = 0.042, one-tailed). However, the difference between the two conditions was not significant for the participants’ level of self-efficacy (t = 0.399, df = 43, p = 0.346, one-tailed) nor strength of self-efficacy (t = 0.508, df = 43, p = 0.307, one-tailed). Watching motivational videos before exercise is an effective performance enhancement; however, more research is needed to further understand its impact on self-efficacy. Keywords Exercise, motivational video, muscular endurance performance, plank exercise, pre- game speech, self-efficacy. Introduction Self-efficacy, a term coined by Bandura (1977), is the most critical self-perception in sport and exercise psychology (Gill and Williams, 2008: 91). Bandura’s work (1997: 3), a fundamental component within the framework of social