Donald Kirkendall, PhD, received his doctorate in exercise physiology from The Ohio State University and went on to teach human anatomy, physiology, and exercise physiology at the University of Wisconsin at Lacrosse and Illinois State University. In 1995 he was recruited to join the sports medicine program at Duke University Medical Center. He went on to join the staff at the University of North Carolina at Chapel Hill (1998-2003). He retired from the Duke Clinical Research Institute in 2015. His research interests focused on sports medicine and physical performance with an emphasis on team sports-especially soccer. Kirkendall is a member of U.S. Soccer’s Medical Advisory Committee, and he was a member of the FÉdÉration Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) from 2004 to 2015. He frequently lectured at coaching clinics and to local and national coaching organizations, and he has lectured to audiences in all six of FIFA’s confederations. Adam Sayers, PhD, is a faculty member at East Tennessee State University (ETSU) in both the global sport leadership department and the department of sport, exercise, recreation, and kinesiology. Sayers was the head coach of women’s soccer at ETSU from 2011 to 2019. In 2018, he became the all-time winningest coach in ETSU history with his 80th win. Sayers holds the Union of European Football Associations (UEFA) A-level coaching license and the United States Soccer Federation (USSF) A-level coaching license and is a sport science staff member with the United States youth women's teams, working with the U16, U18, U19, and U20 national teams. In addition to his coaching qualifications, Sayers is certified by the National Strength and Conditioning Association (NSCA) as a Certified Strength and Conditioning Specialist. He has served as a coach educator within the USSF coach education program and with the Tennessee State Soccer Association. Sayers obtained a PhD in human performance from Middle Tennessee State University in 2006. He has presented his research on various physiological aspects of soccer at national and regional conventions, including the American College of Sports Medicine (ACSM) national meeting and the NSCA National Sport-Specific Training Conference. He is a published author, having contributed several soccer-related articles to peer-reviewed scientific journals as well as several coaching journals and websites.
