Morc Coulson is senior lecturer and the programme leader of Sport and Exercise Science at the University of Sunderland. He is the author of a number of books for fitness professionals including The Advanced Fitness Instructor's Handbook (2008) and Practical Fitness Testing (2009). Sarah Bolitho is Partner, Exact Training and Curriculum and Business Development Coordinator, Fitness Wales. She is the co-author of The Complete Guide to Physical Activity and Mental Health and Exercise Your Way to Health: Stress.