Does unhelpful thinking influence your sporting performance, or the athletes you work with? Athletes of all levels experience barriers to performance beyond the physical challenges they face. These can range from, performance anxiety, overthinking, and lack of concentration, to issues of motivation or difficulties when dealing with team members. ACT - Acceptance and Commitment Therapy - is a modern and effective psychological approach based on a scientific understanding of human thought and emotional processes. ACT uses a practical and easy-to-use framework for skill development through values-based action, commitment, defusion, mindfulness, and acceptance. By utilising ACT, athletes will flourish into their better selves and improve their performances across their sports and beyond. ACT in Sport is a practical workbook that provides a variety of simple strategies for athletes, sport psychologists, and coaches - regardless of their level of ability - for growing their skills. It is a manual for anyone wanting to become familiar with this increasingly popular but poorly understood approach to the psychology of sports performance. More than 20 practical exercises are included, and a free-to-download workbook accompanies the book. Foreword by Patrick Smith and Steven C. Hayes.