Book excerpt: Science and Football VIII showcases the very latest scientific research into the variety of sports known as ‘football’. These include soccer, the national codes (American football, Australian rules football and Gaelic football), and the rugby codes (union and league). Bridging the gap between theory and practice, this book is by far the most comprehensive collection of current research into football, presenting important new work in key areas such as: physiology of training performance analysis fitness assessment nutrition biomechanics injury and rehabilitation youth football environmental physiology psychology in football sociological perspectives in football Science and Football VIII is an essential resource for all sport scientists, trainers, coaches, physical therapists, physicians, psychologists, educational officers and professionals working across the football codes. Chapter 6 of this book is freely available as a downloadable Open Access PDF at http://www.taylorfrancis.com under a Creative Commons Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND) 4.0 license.