The evolution of performance enhancement, prevention of sports injuries and psycho physiological rehabilitation of injuries in today’s athletic world is truly amazing since ancient times, there has been a virtual explosion in the number of physical therapists, trainers, coaches and other scientific team embracing as an integral part of their athlete’s development and rehabilitation with modern scientific techniques. The intention through this book is to make reader to understand the basic principles of pre-competition stress or anxiety and its measurements so that one can refer or understand. It also provides its scientific aspects through reviewing different literatures available on procedures and reliability of physiological measurements. Overall intention of this topic “Physiological Markers for Pre-competition Stress in Sports” is to understand the correct approaches of test selection and regimes, this wide knowledge of physiological measurement shall be useful for sports rehabilitation. The book is intended for understanding, evidence based practice, and resource guide for graduate and post graduate students in athletic trainers, sports physical therapy and other health professionals who is responsible for sports injury rehabilitation.