The relationship between arousal and performance is a vital component in the study of an athlete's performance. When you experience feelings of excitement (or lack thereof) in a competitive sporting situation, the resulting effects can be enormous. One of the fundamental principles of the arousal-performance relationship is the inverted-U hypothesis (Baechle and Earle 2008, 168), developed by Yerkes and Dodson. According to their hypothesis, as arousal levels increase, the individual's performance levels also increase, but only up to a certain point (known as the "optimal" point). The necessary levels of arousal are different in many situations. The "optimal" level depends on the type of activity, skill level and personality of the individual. Below we will detail the Inverted U Hypothesis and how it varies across athletes, sports, and abilities. As briefly mentioned, the inverted-U hypothesis refers to the relationship between arousal and performance. Two psychologists, Yerkes and Dodson, developed the inverted-U hypothesis. The hypothesis focused on the decision-making abilities of mice when presented with different stressors (Arent and Landers 2003, 436). This hypothesis was later modified for application to sport. The inverted-U hypothesis states that at low levels of arousal, performance will be low (i.e. the individual is not aroused enough) and as arousal increases, so does performance, up to the aforementioned "optimal" level (Weinberg and Gould 2010). , 86). After this "optimal" level, if arousal begins to increase, the individual's performance will begin to deteriorate due to the individual's excessive arousal. This is represented by an inverted U (see Figure 1). Excessive arousal can be...... middle of paper......L: Human Kinetics.Cox, Richard H. 2006. Sport Psychology – Concepts and Applications. New York, NY: McGraw-Hill Higher Education. The Inverted-U Model – Balancing Pressure and Performance, 2011. http://www.mindtools.com/pages/article/inverted-u.htm (accessed 12 July 2011) Jarvis, Matt. 2006. Sports Psychology - A Student's Handbook. Hove, East Sussex: Routledge.Motivation and Arousal, 2011.http://en.wikiversity.org/wiki/Motivation_and_emotion/Textbook/Motivation/Arousal (accessed 12 July 2011) Saklofske, Donald H., and Moshe Zeidner. 1995. International Handbook of Personality and Intelligence. New York, NY: Springer.Weinberg, Robert and Daniel Gould. 2010. Fundamentals of Sport and Exercise Psychology.Champaign, IL: Human Kinetics.Woods, Barbara. 1998. Applying psychology to sport. Great Britain: Hodder & Stoughton.