This chapter focuses on the influence of emotional reactions on skilled performance and the necessity for effective emotion regulation to realize expertise in sport. The skills demonstrated by elite athletes across sports are thought by some to reflect innate talent supported by a continuous process of talent development. Emotions are evolutionarily preserved psychophysiological states that ensure survival by adapting the body for action and promoting the attainment of various goals in daily life. The Biopsychosocial Model of challenge and threat provides a useful theoretical framework for understanding how psychological and physiological processes interact as a function of task demands and resource appraisals. Under pressure, the deleterious effects of emotions are amplified, emphasizing the need for performers to experience just the right emotion, with just the right intensity at just the right time to complement current skill level and ensure optimal performance.