This book is aimed at both coaches in competitive and elite sports and interested athletes. It aims to provide guiding and scientifically based information and recommendations on strength training in competitive sports, enabling readers to fully exploit the performance-enhancing potential of training the motor skill of strength. It is explicitly stated that the book does not claim to comprehensively capture the entire complexity of strength training within the specific training context of each sport. In the first part of the work, theoretical fundamentals regarding the motor skill of strength, medical and biological training adaptations, as well as insights into various strength training methods and specific aspects of training are addressed.