Music has a positive effect on performance measures during exercise and sport at submaximal intensities. Purpose: To measure the effects of self-selected motivational music on a 1.5 mile maximal intensity running time trial. Methodology: Subjects were trained male and female runners (N = 14), age 19-34 (M = 24.86). Each subject self-selected and rated a motivational song to be used as treatment in the running trial. The study was conducted as a repeated-measures crossover design in which the subjects were randomly assigned and ran two trials with and without motivational music. The variables of performance time, average heart rate, and rating of perceived exertion (RPE) were measured. The results from the data were analyzed using dependent t tests. The alpha level was set at p < 0.05. Results: On average, the subjects ran the trial 11 seconds faster with music, but the motivational music condition did not significantly improve performance time, t(13) = 1.754, p = 0.0515, r = 0.43. Subjects experienced a higher average heart rate of 5.2 beats per minute faster with the music condition, although the increase was not statistically significant, t(12) = -1.637, p = 0.064, r = 0.42. The music condition significantly lowered subjects' RPE by 0.5 points on a scale of 0-10, t(13) = 2.446, p = 0.029, r = 0.56. Conclusion: The results of this study may help with the application of music in enduring high intensity exercise, which is essential as the research on the relationship between high intensity exercise and improved health markers continues to emerge.