The emotional reactions of athletes in sports competitions are not only fascinating to the spectators, but also illustrate that emotions are transmitted to the outside world, thus suggesting that they are not just intrapersonal processes. From a metacognitive perspective it is important to understand why these reactions occur and how they affect sports performance. In this study the antecedents and consequences of outward emotional reactions were explored using a naturalistic qualitative video-assisted procedure. Twelve German table tennis players were video-recorded during competitive matches in their regular season. Subsequently, based on the footage, self-confrontational interviews were conducted focusing on the antecedents and consequences of outward emotional reactions. The analysis revealed several factors related to whether or not outward emotional reactions were displayed, ranging from more malleable (e.g., state-like psychological states) to less malleable (e.g., trait-like factors). In addition, the analysis revealed how outward emotional reactions have performance-related effects on one's own mental state (e.g., one's concentration) and on the psychological state of the opponent (e.g., the opponent's confidence). The present findings suggest that it is important to create an awareness of antecedents of outward emotional reactions in athletes in order to improve the use of psychological skills by athletes to control their emotional responses. In addition, the results point to the importance of the behavioural component of emotions in the emotion-performance relationship, as various intra- and interpersonal consequences that interact with the consequences of the purely subjective emotion experience were identified.