The chapter discusses the benefits of warm-up and flexibility for performance and injury prevention. It explains the difference between warm-up and stretching, how to measure flexibility, and the advantages and disadvantages of increased range of motion. Normal static flexibility is the typical joint movement between limited and excessive range of motion. The literature challenges common beliefs about flexibility's role in injury risk and performance. Various stretches can increase flexibility, but it's important to understand the limitations. The chapter provides guidelines for appropriate stretching exercises.