It has been nearly fifteen years since mindfulness- and acceptance-based interventions were formally proposed as an alternative model in sport psychology for the purpose of both enhanced performance and enhanced psychological and general well-being of athletes (Moore & Gardner, 2001). In that time, theoretical insights and empirical advancements have broadened our knowledge base and have shaped these contemporary interventions in exciting ways (Gardner & Moore, 2012). This chapter looks back over the past fifteen years to illustrate how far third-wave thinkers, like all of us, have come, by discussing the formation and use of mindfulness- and acceptance-based models within sport psychology and the current state of the science of associated protocols for the purpose of athletic performance enhancement and overall psychosocial well-being. Herein, I also hope to accentuate the fundamental differences between these procedures and those of traditional cognitive, behaviorally oriented sport psychology practice and address some of the misconceptions often heard about mindfulness- and acceptance-based models and procedures.

Since the first major incorporation of mindfulness- and acceptance-based frameworks into sport psychology occurred over fifteen years ago with the advent of the Mindfulness-Acceptance-Commitment (MAC) approach, the theoretical underpinnings central to traditional models of sport psychology have faced notable challenge. The long-unquestioned traditional psychological skills training (PST) model suggests that internal states (i.e., cognitions, emotions, somatic sensations) need to be modified, reduced, or avoided in order to enhance athletic performance and reach peak performance states. I once believed this. I once incorporated these traditional theories and associated techniques with elite athletes across multiple professional sports. And I once taught and encouraged graduate students to believe this and to take this “tried-and-true” model with them as they embarked upon their own careers.

Yet as new evidence-based developments within clinical psychology emerged, and clinical psychology witnessed the profound and seismic shift in how we conceptualize and approach internal phenomena, I admit that I rightfully started to question my long-held allegiance to traditional forms of sport psychology practice. It was an interesting phenomenon, actually, because as a clinical psychologist, I spent my career at the front of the clinical empirical developments and maintained an unquenched thirst for rigorous scientific advancement.