Journal of Sports Science 5 (2017) 146-156 doi: 10.17265/2332-7839/2017.03.002 Examining the Interrelationships between Motivation, Conscientiousness, and Individual Endurance Sport Performance Joanne Perry, Michael Ross, Jeremiah Weinstock and Jeffrey Gfeller Department of Psychology, Saint Louis University, St. Louis, Missouri 63108, USA Abstract: Personality traits and motivation have been predictive of athletic success. Conscientiousness, intrinsic motivation (IM), and extrinsic motivation (EM) positively predict sport performance, while amotivation (AM) has a negative impact. This study examined the effects of both sport motivation and conscientiousness on athletic performance. Methods included a cross-sectional survey study of endurance athletes (N = 73); including runners (56.1%), swimmers (19.2%), triathletes (6.8%), rowers (2.7%), and multi-sport athletes (15.1%). Conscientiousness and motivation were assessed using questionnaires. Subjective ratings and objective scores of a recent performance(s) were collected. Regression analyses demonstrated that conscientiousness positively predicted IM and negatively predicted AM. AM negatively predicted subjective performance. IM and EM were not significant predictors of subjective performance. No variable significantly predicted objective performance. Results support the deleterious role of AM in performance. Compared to IM and EM, AM might be a more relevant construct when predicting performance in a sample of athletes with varying degrees of commitment. This construct may be of particular interest to clinicians due to its association with athletic burnout. Conscientiousness may serve as a protective factor against burnout. Key words: Conscientiousness, motivation, athletic performance, athletic burnout. 1. Introduction Understanding the relationship between personality traits, individual difference variables, and athletic performance is important for predicting athletic success and can provide valuable information to athletes, coaches, and other athletic support personnel. Specifically, conscientiousness, a personality factor, and motivation, an individual difference variable, are predictive of athletic success [1-4]. Differences in personality traits explain 20% to 45% of the variance in athletic performance [2]. Additionally, the type of motivation present in athletes can be influential in determining outcomes in sport performance [5-7]. Conscientiousness relates to one’s readiness to pursue athletic success, while motivation impacts an individual’s willingness to engage in the necessary behaviors [8]. The field of sport psychology has yet to Corresponding author: Joanne E. Perry, M.S., doctoral candidate, research field: clinical sport psychology. examine the interaction and/or additive effects of motivation and conscientiousness on individual endurance sport performance. The current study simultaneously examined these variables in order to better understand the combined predictive ability of both conscientiousness and motivation on individual endurance sport performance. Conscientiousness is one of five personality traits included in the Big Five model of personality, which represents a universal, cross-cultural structure of individual differences [9]. Conscientiousness is related to being task and goal oriented, as well as being able to delay immediate gratification. Individuals with high levels of conscientiousness are described as orderly, industrious, and disciplined [10]. On the other hand, individuals with low levels of conscientiousness are described as undisciplined, lacking attention to detail, and unreliable [10]. This trait has been positively associated with many types of performance including D DAVID PUBLISHING